FERC Form

THIS FILING IS

Item 1:

☑ An Initial (Original) Submission

☐ Resubmission No.




FERC FINANCIAL REPORT FERC FORM No. 1: Annual Report of Major Electric Utilities, Licensees and Others and Supplemental Form 3-Q: Quarterly Financial Report

These reports are mandatory under the Federal Power Act, Sections 3, 4(a), 304 and 309, and 18 CFR 141.1 and 141.400. Failure to report may result in criminal fines, civil penalties and other sanctions as provided by law. The Federal Energy Regulatory Commission does not consider these reports to be of confidential nature

Exact Legal Name of Respondent (Company)

NorthWestern Corporation

Year/Period of Report

End of:

2024

INSTRUCTIONS FOR FILING FERC FORM NOS. 1 and 3-Q

GENERAL INFORMATION

Purpose
FERC Form No. 1 (FERC Form 1) is an annual regulatory requirement for Major electric utilities, licensees and others (18 C.F.R. § 141.1). FERC Form No. 3-Q ( FERC Form 3-Q) is a quarterly regulatory requirement which supplements the annual financial reporting requirement (18 C.F.R. § 141.400). These reports are designed to collect financial and operational information from electric utilities, licensees and others subject to the jurisdiction of the Federal Energy Regulatory Commission. These reports are also considered to be non-confidential public use forms.
Who Must Submit
Each Major electric utility, licensee, or other, as classified in the Commission’s Uniform System of Accounts Prescribed for Public Utilities, Licensees, and Others Subject To the Provisions of The Federal Power Act (18 C.F.R. Part 101), must submit FERC Form 1 (18 C.F.R. § 141.1), and FERC Form 3-Q (18 C.F.R. § 141.400).
Note: Major means having, in each of the three previous calendar years, sales or transmission service that exceeds one of the following:
1. one million megawatt hours of total annual sales,
2. 100 megawatt hours of annual sales for resale,
3. 500 megawatt hours of annual power exchanges delivered, or
4. 500 megawatt hours of annual wheeling for others (deliveries plus losses).

What and Where to Submit

Submit FERC Form Nos. 1 and 3-Q electronically through the eCollection portal at https://eCollection.ferc.gov, and according to the specifications in the Form 1 and 3-Q taxonomies.
The Corporate Officer Certification must be submitted electronically as part of the FERC Forms 1 and 3-Q filings.
Submit immediately upon publication, by either eFiling or mail, two (2) copies to the Secretary of the Commission, the latest Annual Report to Stockholders. Unless eFiling the Annual Report to Stockholders, mail the stockholders report to the Secretary of the Commission at:
Secretary
Federal Energy Regulatory Commission 888 First Street, NE
Washington, DC 20426

For the CPA Certification Statement, submit within 30 days after filing the FERC Form 1, a letter or report (not applicable to filers classified as Class C or Class D prior to January 1, 1984). The CPA Certification Statement can be either eFiled or mailed to the Secretary of the Commission at the address above.

The CPA Certification Statement should:

Attest to the conformity, in all material aspects, of the below listed (schedules and pages) with the Commission's applicable Uniform System of Accounts (including applicable notes relating thereto and the Chief Accountant's published accounting releases), and

Be signed by independent certified public accountants or an independent licensed public accountant certified or licensed by a regulatory authority of a State or other political subdivision of the U. S. (See 18 C.F.R. §§ 41.10-41.12 for specific qualifications.)

Schedules	Pages
Comparative Balance Sheet	110-113
Statement of Income	114-117
Statement of Retained Earnings	118-119
Statement of Cash Flows	120-121
Notes to Financial Statements	122-123

The following format must be used for the CPA Certification Statement unless unusual circumstances or conditions, explained in the letter or report, demand that it be varied. Insert parenthetical phrases only when exceptions are reported.
“In connection with our regular examination of the financial statements of [COMPANY NAME] for the year ended on which we have reported separately under date of [DATE], we have also reviewed schedules [NAME OF SCHEDULES] of FERC Form No. 1 for the year filed with the Federal Energy Regulatory Commission, for conformity in all material respects with the requirements of the Federal Energy Regulatory Commission as set forth in its applicable Uniform System of Accounts and published accounting releases. Our review for this purpose included such tests of the accounting records and such other auditing procedures as we considered necessary in the circumstances.
Based on our review, in our opinion the accompanying schedules identified in the preceding paragraph (except as noted below) conform in all material respects with the accounting requirements of the Federal Energy Regulatory Commission as set forth in its applicable Uniform System of Accounts and published accounting releases.” The letter or report must state which, if any, of the pages above do not conform to the Commission’s requirements. Describe the discrepancies that exist.
Filers are encouraged to file their Annual Report to Stockholders, and the CPA Certification Statement using eFiling. Further instructions are found on the Commission’s website at https://www.ferc.gov/ferc-online/ferc-online/frequently-asked-questions-faqs-efilingferc-online.
Federal, State, and Local Governments and other authorized users may obtain additional blank copies of FERC Form 1 and 3-Q free of charge from https://www.ferc.gov/general-information-0/electric-industry-forms.

When to Submit
FERC Forms 1 and 3-Q must be filed by the following schedule:
1. FERC Form 1 for each year ending December 31 must be filed by April 18th of the following year (18 CFR § 141.1), and
2. FERC Form 3-Q for each calendar quarter must be filed within 60 days after the reporting quarter (18 C.F.R. § 141.400).
Where to Send Comments on Public Reporting Burden.
The public reporting burden for the FERC Form 1 collection of information is estimated to average 1,168 hours per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data-needed, and completing and reviewing the collection of information. The public reporting burden for the FERC Form 3-Q collection of information is estimated to average 168 hours per response.
Send comments regarding these burden estimates or any aspect of these collections of information, including suggestions for reducing burden, to the Federal Energy Regulatory Commission, 888 First Street NE, Washington, DC 20426 (Attention: Information Clearance Officer); and to the Office of Information and Regulatory Affairs, Office of Management and Budget, Washington, DC 20503 (Attention: Desk Officer for the Federal Energy Regulatory Commission). No person shall be subject to any penalty if any collection of information does not display a valid control number (44 U.S.C. § 3512 (a)).

GENERAL INSTRUCTIONS

Prepare this report in conformity with the Uniform System of Accounts (18 CFR Part 101) (USofA). Interpret all accounting words and phrases in accordance with the USofA.
Enter in whole numbers (dollars or MWH) only, except where otherwise noted. (Enter cents for averages and figures per unit where cents are important. The truncating of cents is allowed except on the four basic financial statements where rounding is required.) The amounts shown on all supporting pages must agree with the amounts entered on the statements that they support. When applying thresholds to determine significance for reporting purposes, use for balance sheet accounts the balances at the end of the current reporting period, and use for statement of income accounts the current year's year to date amounts.
Complete each question fully and accurately, even if it has been answered in a previous report. Enter the word "None" where it truly and completely states the fact.
For any page(s) that is not applicable to the respondent, omit the page(s) and enter "NA," "NONE," or "Not Applicable" in column (d) on the List of Schedules, pages 2 and 3.
Enter the month, day, and year for all dates. Use customary abbreviations. The "Date of Report" included in the header of each page is to be completed only for resubmissions (see VII. below).
Generally, except for certain schedules, all numbers, whether they are expected to be debits or credits, must be reported as positive. Numbers having a sign that is different from the expected sign must be reported by enclosing the numbers in parentheses.
For any resubmissions, please explain the reason for the resubmission in a footnote to the data field.
Do not make references to reports of previous periods/years or to other reports in lieu of required entries, except as specifically authorized.
Wherever (schedule) pages refer to figures from a previous period/year, the figures reported must be based upon those shown by the report of the previous period/year, or an appropriate explanation given as to why the different figures were used.
Schedule specific instructions are found in the applicable taxonomy and on the applicable blank rendered form.

Definitions for statistical classifications used for completing schedules for transmission system reporting are as follows:

FNS - Firm Network Transmission Service for Self. "Firm" means service that can not be interrupted for economic reasons and is intended to remain reliable even under adverse conditions. "Network Service" is Network Transmission Service as described in Order No. 888 and the Open Access Transmission Tariff. "Self" means the respondent.

FNO - Firm Network Service for Others. "Firm" means that service cannot be interrupted for economic reasons and is intended to remain reliable even under adverse conditions. "Network Service" is Network Transmission Service as described in Order No. 888 and the Open Access Transmission Tariff.

LFP - for Long-Term Firm Point-to-Point Transmission Reservations. "Long-Term" means one year or longer and” firm" means that service cannot be interrupted for economic reasons and is intended to remain reliable even under adverse conditions. "Point-to-Point Transmission Reservations" are described in Order No. 888 and the Open Access Transmission Tariff. For all transactions identified as LFP, provide in a footnote the termination date of the contract defined as the earliest date either buyer or seller can unilaterally cancel the contract.

OLF - Other Long-Term Firm Transmission Service. Report service provided under contracts which do not conform to the terms of the Open Access Transmission Tariff. "Long-Term" means one year or longer and “firm” means that service cannot be interrupted for economic reasons and is intended to remain reliable even under adverse conditions. For all transactions identified as OLF, provide in a footnote the termination date of the contract defined as the earliest date either buyer or seller can unilaterally get out of the contract.

SFP - Short-Term Firm Point-to-Point Transmission Reservations. Use this classification for all firm point-to-point transmission reservations, where the duration of each period of reservation is less than one-year.

NF - Non-Firm Transmission Service, where firm means that service cannot be interrupted for economic reasons and is intended to remain reliable even under adverse conditions.

OS - Other Transmission Service. Use this classification only for those services which can not be placed in the above-mentioned classifications, such as all other service regardless of the length of the contract and service FERC Form. Describe the type of service in a footnote for each entry.

AD - Out-of-Period Adjustments. Use this code for any accounting adjustments or "true-ups" for service provided in prior reporting periods. Provide an explanation in a footnote for each adjustment.

DEFINITIONS

Commission Authorization (Comm. Auth.) -- The authorization of the Federal Energy Regulatory Commission, or any other Commission. Name the commission whose authorization was obtained and give date of the authorization.
Respondent -- The person, corporation, licensee, agency, authority, or other Legal entity or instrumentality in whose behalf the report is made.

EXCERPTS FROM THE LAW

Federal Power Act, 16 U.S.C. § 791a-825r

Sec. 3. The words defined in this section shall have the following meanings for purposes of this Act, to with:

’Corporation' means any corporation, joint-stock company, partnership, association, business trust, organized group of persons, whether incorporated or not, or a receiver or receivers, trustee or trustees of any of the foregoing. It shall not include 'municipalities, as hereinafter defined;
'Person' means an individual or a corporation;
'Licensee, means any person, State, or municipality Licensed under the provisions of section 4 of this Act, and any assignee or successor in interest thereof;

'municipality means a city, county, irrigation district, drainage district, or other political subdivision or agency of a State competent under the Laws thereof to carry and the business of developing, transmitting, unitizing, or distributing power; ......

"project' means. a complete unit of improvement or development, consisting of a power house, all water conduits, all dams and appurtenant works and structures (including navigation structures) which are a part of said unit, and all storage, diverting, or fore bay reservoirs directly connected therewith, the primary line or lines transmitting power there from to the point of junction with the distribution system or with the interconnected primary transmission system, all miscellaneous structures used and useful in connection with said unit or any part thereof, and all water rights, rights-of-way, ditches, dams, reservoirs, Lands, or interest in Lands the use and occupancy of which are necessary or appropriate in the maintenance and operation of such unit;

"Sec. 4. The Commission is hereby authorized and empowered

'To make investigations and to collect and record data concerning the utilization of the water 'resources of any region to be developed, the water-power industry and its relation to other industries and to interstate or foreign commerce, and concerning the location, capacity, development costs, and relation to markets of power sites; ... to the extent the Commission may deem necessary or useful for the purposes of this Act."

"Sec. 304.

Every Licensee and every public utility shall file with the Commission such annual and other periodic or special* reports as the Commission may by rules and regulations or other prescribe as necessary or appropriate to assist the Commission in the proper administration of this Act. The Commission may prescribe the manner and FERC Form in which such reports shall be made, and require from such persons specific answers to all questions upon which the Commission may need information. The Commission may require that such reports shall include, among other things, full information as to assets and Liabilities, capitalization, net investment, and reduction thereof, gross receipts, interest due and paid, depreciation, and other reserves, cost of project and other facilities, cost of maintenance and operation of the project and other facilities, cost of renewals and replacement of the project works and other facilities, depreciation, generation, transmission, distribution, delivery, use, and sale of electric energy. The Commission may require any such person to make adequate provision for currently determining such costs and other facts. Such reports shall be made under oath unless the Commission otherwise specifies*.10

"Sec. 309.

The Commission shall have power to perform any and all acts, and to prescribe, issue, make, and rescind such orders, rules and regulations as it may find necessary or appropriate to carry out the provisions of this Act. Among other things, such rules and regulations may define accounting, technical, and trade terms used in this Act; and may prescribe the FERC Form or FERC Forms of all statements, declarations, applications, and reports to be filed with the Commission, the information which they shall contain, and the time within which they shall be field..."

GENERAL PENALTIES

The Commission may assess up to $1 million per day per violation of its rules and regulations. See FPA § 316(a) (2005), 16 U.S.C. § 825o(a).

FERC FORM NO.

REPORT OF MAJOR ELECTRIC UTILITIES, LICENSEES AND OTHER

IDENTIFICATION

01 Exact Legal Name of Respondent

NorthWestern Corporation

02 Year/ Period of Report

End of:

2024

03 Previous Name and Date of Change (If name changed during year)

04 Address of Principal Office at End of Period (Street, City, State, Zip Code)

3010 West 69th Street, Sioux Falls, SD 57108

05 Name of Contact Person

Evan VerWey

06 Title of Contact Person

Manager of Financial Reporting

07 Address of Contact Person (Street, City, State, Zip Code)

3010 West 69th Street, Sioux Falls, SD 57108

08 Telephone of Contact Person, Including Area Code

605-978-2906

09 This Report is An Original / A Resubmission

(1)

☑ An Original

(2)

☐ A Resubmission

10 Date of Report (Mo, Da, Yr)

12/31/2024

Annual Corporate Officer Certification

The undersigned officer certifies that:

I have examined this report and to the best of my knowledge, information, and belief all statements of fact contained in this report are correct statements of the business affairs of the respondent and the financial statements, and other financial information contained in this report, conform in all material respects to the Uniform System of Accounts.

01 Name

Jeff Berzina

02 Title

Controller

03 Signature

Jeff Berzina

04 Date Signed (Mo, Da, Yr)

02/28/2025

Title 18, U.S.C. 1001 makes it a crime for any person to knowingly and willingly to make to any Agency or Department of the United States any false, fictitious or fraudulent statements as to any matter within its jurisdiction.

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

LIST OF SCHEDULES (Electric Utility)
Enter in column (c) the terms "none," "not applicable," or "NA," as appropriate, where no information or amounts have been reported for certain pages. Omit pages where the respondents are "none," "not applicable," or "NA".
Line No.	Title of Schedule (a)	Reference Page No. (b)	Remarks (c)
	ScheduleIdentificationAbstract Identification	1
	ScheduleListOfSchedulesAbstract List of Schedules	2
1	ScheduleGeneralInformationAbstract General Information	101
2	ScheduleControlOverRespondentAbstract Control Over Respondent	102
3	ScheduleCorporationsControlledByRespondentAbstract Corporations Controlled by Respondent	103
4	ScheduleOfficersAbstract Officers	104
5	ScheduleDirectorsAbstract Directors	105
6	ScheduleInformationOnFormulaRatesAbstract Information on Formula Rates	106
7	ScheduleImportantChangesDuringTheQuarterYearAbstract Important Changes During the Year	108
8	ScheduleComparativeBalanceSheetAbstract Comparative Balance Sheet	110
9	ScheduleStatementOfIncomeAbstract Statement of Income for the Year	114
10	ScheduleRetainedEarningsAbstract Statement of Retained Earnings for the Year	118
12	ScheduleStatementOfCashFlowsAbstract Statement of Cash Flows	120
12	ScheduleNotesToFinancialStatementsAbstract Notes to Financial Statements	122
13	ScheduleStatementOfAccumulatedOtherComprehensiveIncomeAndHedgingActivitiesAbstract Statement of Accum Other Comp Income, Comp Income, and Hedging Activities	122a
14	ScheduleSummaryOfUtilityPlantAndAccumulatedProvisionsForDepreciationAmortizationAndDepletionAbstract Summary of Utility Plant & Accumulated Provisions for Dep, Amort & Dep	200
15	ScheduleNuclearFuelMaterialsAbstract Nuclear Fuel Materials	202	Not Applicable
16	ScheduleElectricPlantInServiceAbstract Electric Plant in Service	204
17	ScheduleElectricPropertyLeasedToOthersAbstract Electric Plant Leased to Others	213	Not Applicable
18	ScheduleElectricPlantHeldForFutureUseAbstract Electric Plant Held for Future Use	214
19	ScheduleConstructionWorkInProgressElectricAbstract Construction Work in Progress-Electric	216
20	ScheduleAccumulatedProvisionForDepreciationOfElectricUtilityPlantAbstract Accumulated Provision for Depreciation of Electric Utility Plant	219
21	ScheduleInvestmentsInSubsidiaryCompaniesAbstract Investment of Subsidiary Companies	224
22	ScheduleMaterialsAndSuppliesAbstract Materials and Supplies	227
23	ScheduleAllowanceInventoryAbstract Allowances	228
24	ScheduleExtraordinaryPropertyLossesAbstract Extraordinary Property Losses	230a	Not Applicable
25	ScheduleUnrecoveredPlantAndRegulatoryStudyCostsAbstract Unrecovered Plant and Regulatory Study Costs	230b	Not Applicable
26	ScheduleTransmissionServiceAndGenerationInterconnectionStudyCostsAbstract Transmission Service and Generation Interconnection Study Costs	231
27	ScheduleOtherRegulatoryAssetsAbstract Other Regulatory Assets	232
28	ScheduleMiscellaneousDeferredDebitsAbstract Miscellaneous Deferred Debits	233
29	ScheduleAccumulatedDeferredIncomeTaxesAbstract Accumulated Deferred Income Taxes	234
30	ScheduleCapitalStockAbstract Capital Stock	250
31	ScheduleOtherPaidInCapitalAbstract Other Paid-in Capital	253
32	ScheduleCapitalStockExpenseAbstract Capital Stock Expense	254b	Not Applicable
33	ScheduleLongTermDebtAbstract Long-Term Debt	256
34	ScheduleReconciliationOfReportedNetIncomeWithTaxableIncomeForFederalIncomeTaxesAbstract Reconciliation of Reported Net Income with Taxable Inc for Fed Inc Tax	261
35	ScheduleTaxesAccruedPrepaidAndChargedDuringYearDistributionOfTaxesChargedAbstract Taxes Accrued, Prepaid and Charged During the Year	262
36	ScheduleAccumulatedDeferredInvestmentTaxCreditsAbstract Accumulated Deferred Investment Tax Credits	266
37	ScheduleOtherDeferredCreditsAbstract Other Deferred Credits	269
38	ScheduleAccumulatedDeferredIncomeTaxesAcceleratedAmortizationPropertyAbstract Accumulated Deferred Income Taxes-Accelerated Amortization Property	272	Not Applicable
39	ScheduleAccumulatedDeferredIncomeTaxesOtherPropertyAbstract Accumulated Deferred Income Taxes-Other Property	274
40	ScheduleAccumulatedDeferredIncomeTaxesOtherAbstract Accumulated Deferred Income Taxes-Other	276
41	ScheduleOtherRegulatoryLiabilitiesAbstract Other Regulatory Liabilities	278
42	ScheduleElectricOperatingRevenuesAbstract Electric Operating Revenues	300
43	ScheduleRegionalTransmissionServiceRevenuesAbstract Regional Transmission Service Revenues (Account 457.1)	302	Not Applicable
44	ScheduleSalesOfElectricityByRateSchedulesAbstract Sales of Electricity by Rate Schedules	304
45	ScheduleSalesForResaleAbstract Sales for Resale	310
46	ScheduleElectricOperationsAndMaintenanceExpensesAbstract Electric Operation and Maintenance Expenses	320
47	SchedulePurchasedPowerAbstract Purchased Power	326
48	ScheduleTransmissionOfElectricityForOthersAbstract Transmission of Electricity for Others	328
49	ScheduleTransmissionOfElectricityByIsoOrRtoAbstract Transmission of Electricity by ISO/RTOs	331	Not Applicable
50	ScheduleTransmissionOfElectricityByOthersAbstract Transmission of Electricity by Others	332
51	ScheduleMiscellaneousGeneralExpensesAbstract Miscellaneous General Expenses-Electric	335
52	ScheduleDepreciationDepletionAndAmortizationAbstract Depreciation and Amortization of Electric Plant (Account 403, 404, 405)	336
53	ScheduleRegulatoryCommissionExpensesAbstract Regulatory Commission Expenses	350
54	ScheduleResearchDevelopmentOrDemonstrationExpendituresAbstract Research, Development and Demonstration Activities	352	Not Applicable
55	ScheduleDistributionOfSalariesAndWagesAbstract Distribution of Salaries and Wages	354
56	ScheduleCommonUtilityPlantAndExpensesAbstract Common Utility Plant and Expenses	356
57	ScheduleAmountsIncludedInIsoOrRtoSettlementAbstract Amounts included in ISO/RTO Settlement Statements	397	Not Applicable
58	SchedulePurchasesSalesOfAncillaryServicesAbstract Purchase and Sale of Ancillary Services	398
59	ScheduleMonthlyTransmissionSystemPeakLoadAbstract Monthly Transmission System Peak Load	400
60	ScheduleMonthlyIsoOrRtoTransmissionSystemPeakLoadAbstract Monthly ISO/RTO Transmission System Peak Load	400a	Not Applicable
61	ScheduleElectricEnergyAccountAbstract Electric Energy Account	401a
62	ScheduleMonthlyPeakAndOutputAbstract Monthly Peaks and Output	401b
63	ScheduleSteamElectricGeneratingPlantStatisticsAbstract Steam Electric Generating Plant Statistics	402
64	ScheduleHydroelectricGeneratingPlantStatisticsAbstract Hydroelectric Generating Plant Statistics	406
65	SchedulePumpedStorageGeneratingPlantStatisticsAbstract Pumped Storage Generating Plant Statistics	408	Not Applicable
66	ScheduleGeneratingPlantStatisticsAbstract Generating Plant Statistics Pages	410
66.1	ScheduleEnergyStorageOperationsLargePlantsAbstract Energy Storage Operations (Large Plants)	414
66.2	ScheduleEnergyStorageOperationsSmallPlantsAbstract Energy Storage Operations (Small Plants)	419
67	ScheduleTransmissionLineStatisticsAbstract Transmission Line Statistics Pages	422
68	ScheduleTransmissionLinesAddedAbstract Transmission Lines Added During Year	424	None
69	ScheduleSubstationsAbstract Substations	426
70	ScheduleTransactionsWithAssociatedAffiliatedCompaniesAbstract Transactions with Associated (Affiliated) Companies	429
71	FootnoteDataAbstract Footnote Data	450
	StockholdersReportsAbstract Stockholders' Reports (check appropriate box)
	Stockholders' Reports Check appropriate box: ☐ Two copies will be submitted ☑ No annual report to stockholders is prepared

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

GENERAL INFORMATION
1. Provide name and title of officer having custody of the general corporate books of account and address of office where the general corporate books are kept, and address of office where any other corporate books of account are kept, if different from that where the general corporate books are kept. Jeff B. Berzina Controller 3010 West 69th Street Sioux Falls, SD 57108
2. Provide the name of the State under the laws of which respondent is incorporated, and date of incorporation. If incorporated under a special law, give reference to such law. If not incorporated, state that fact and give the type of organization and the date organized. State of Incorporation: DE Date of Incorporation: 1923-11-27 Incorporated Under Special Law:
3. If at any time during the year the property of respondent was held by a receiver or trustee, give (a) name of receiver or trustee, (b) date such receiver or trustee took possession, (c) the authority by which the receivership or trusteeship was created, and (d) date when possession by receiver or trustee ceased. (a) Name of Receiver or Trustee Holding Property of the Respondent: (b) Date Receiver took Possession of Respondent Property: (c) Authority by which the Receivership or Trusteeship was created: (d) Date when possession by receiver or trustee ceased:
4. State the classes or utility and other services furnished by respondent during the year in each State in which the respondent operated. Electric and Natural Gas Utility in Montana; Electric Utility in Wyoming (Yellowstone National Park); and Propane in Montana.
5. Have you engaged as the principal accountant to audit your financial statements an accountant who is not the principal accountant for your previous year's certified financial statements? (1) ☐ Yes (2) ☑ No

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

CONTROL OVER RESPONDENT
1. If any corporation, business trust, or similar organization or a combination of such organizations jointly held control over the respondent at the end of the year, state name of controlling corporation or organization, manner in which control was held, and extent of control. If control was in a holding company organization, show the chain of ownership or control to the main parent company or organization. If control was held by a trustee(s), state name of trustee(s), name of beneficiary or beneficiaries for whom trust was maintained, and purpose of the trust.

Respondent is a wholly-owned, direct subsidiary of NorthWestern Energy Group, Inc. At December 31, 2024, NorthWestern Energy Group, Inc. owned 100% of the common stock of Respondent.

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

CORPORATIONS CONTROLLED BY RESPONDENT
Report below the names of all corporations, business trusts, and similar organizations, controlled directly or indirectly by respondent at any time during the year. If control ceased prior to end of year, give particulars (details) in a footnote. If control was by other means than a direct holding of voting rights, state in a footnote the manner in which control was held, naming any intermediaries involved. If control was held jointly with one or more other interests, state the fact in a footnote and name the other interests. Definitions See the Uniform System of Accounts for a definition of control. Direct control is that which is exercised without interposition of an intermediary. Indirect control is that which is exercised by the interposition of an intermediary which exercises direct control. Joint control is that in which neither interest can effectively control or direct action without the consent of the other, as where the voting control is equally divided between two holders, or each party holds a veto power over the other. Joint control may exist by mutual agreement or understanding between two or more parties who together have control within the meaning of the definition of control in the Uniform System of Accounts, regardless of the relative voting rights of each party.
Line No.	NameOfCompanyControlledByRespondent Name of Company Controlled (a)	CompanyControlledByRespondentKindOfBusinessDescription Kind of Business (b)	VotingStockOwnedByRespondentPercentage Percent Voting Stock Owned (c)	FootnoteReferences Footnote Ref. (d)
1	Canadian-Montana Pipe Line Corporation	Owns natural gas pipeline	100
2	Havre Pipeline Company, LLC	Natural gas transmission and gathering system	96
3	Clarkfork and Blackfoot, LLC	Owned a former hydro facility in Montana	100
4	Lodge Creek Pipelines, LLC	Natural gas gathering system	100
5	Willow Creek Gathering, LLC	Natural gas gathering system	100

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

OFFICERS
Report below the name, title and salary for each executive officer whose salary is $50,000 or more. An "executive officer" of a respondent includes its president, secretary, treasurer, and vice president in charge of a principal business unit, division or function (such as sales, administration or finance), and any other person who performs similar policy making functions. If a change was made during the year in the incumbent of any position, show name and total remuneration of the previous incumbent, and the date the change in incumbency was made.
Line No.	OfficerTitle Title (a)	OfficerName Name of Officer (b)	OfficerSalary Salary for Year (c)	DateOfficerIncumbencyStarted Date Started in Period (d)	DateOfficerIncumbencyEnded Date Ended in Period (e)
1	President and Chief Executive Officer	Brian Bird	873,077
2	Vice President, Chief Financial Officer	Crystal Lail	493,101
3	Vice President, General Counsel and Federal Government Affairs	Shannon Heim	364,615
4	Vice President, Asset Management & Business Development	Bleau Lafave	264,620
5	Vice President, Customer Care, Communications, and Human Resources	Bobbi Schroeppel	344,347
6	Vice President, Regulatory Affairs	Cyndee Fang	177,077		2024-09-03
7	Vice President, Distribution	Jason Merkel	273,656
8	Vice President, Technology	Jeanne Vold	277,409
9	Vice President, Supply and Montana Government Affairs	John Hines	341,065
10	Vice President, Transmission	Michael Cashell	340,729

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

DIRECTORS
Report below the information called for concerning each director of the respondent who held office at any time during the year. Include in column (a), name and abbreviated titles of the directors who are officers of the respondent. Provide the principle place of business in column (b), designate members of the Executive Committee in column (c), and the Chairman of the Executive Committee in column (d).
Line No.	NameAndTitleOfDirector Name (and Title) of Director (a)	PrincipalBusinessAddress Principal Business Address (b)	MemberOfTheExecutiveCommittee Member of the Executive Committee (c)	ChairmanOfTheExecutiveCommittee Chairman of the Executive Committee (d)
1	Brian Bird (President and Chief Executive Officer)	Sioux Falls, South Dakota	false	false
2	Crystal Lail (Vice President, Chief Financial Officer)	Sioux Falls, South Dakota	false	false
3	Shannon Heim (Vice President, General Counsel and Federal Government Affairs)	Helena, Montana	false	false
4	Bleau Lafave (Vice President, Asset Management & Business Development)	Sioux Falls, South Dakota	false	false
5	Bobbi Schroeppel (Vice President, Customer Care, Communications, and Human Resources)	Sioux Falls, South Dakota	false	false
6	Cyndee Fang (Vice President, Regulatory Affairs)	Helena, Montana	false	false
7	Jason Merkel (Vice President, Distribution)	Helena, Montana	false	false
8	Jeanne Vold (Vice President, Technology)	Sioux Falls, South Dakota	false	false
9	John Hines (Vice President, Supply and Montana Government Affairs)	Helena, Montana	false	false
10	Michael Cashell (Vice President, Transmission)	Butte, Montana	false	false

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

INFORMATION ON FORMULA RATES
Does the respondent have formula rates?		☑ Yes ☐ No
Please list the Commission accepted formula rates including FERC Rate Schedule or Tariff Number and FERC proceeding (i.e. Docket No) accepting the rate(s) or changes in the accepted rate.
Line No.	RateScheduleTariffNumber FERC Rate Schedule or Tariff Number (a)	ProceedingDocketNumber FERC Proceeding (b)
1	Montana OATT, Attachment O, Formula Rate Protocols and Template	ER24-1668-000

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

INFORMATION ON FORMULA RATES - FERC Rate Schedule/Tariff Number FERC Proceeding
Does the respondent file with the Commission annual (or more frequent) filings containing the inputs to the formula rate(s)?			☑ Yes ☐ No
If yes, provide a listing of such filings as contained on the Commission's eLibrary website.
Line No.	AccessionNumber Accession No. (a)	DocumentDate Document Date / Filed Date (b)	DocketNumber Docket No. (c)	DescriptionOfFiling Description (d)	RateScheduleTariffNumber Formula Rate FERC Rate Schedule Number or Tariff Number (e)
1	20241202-5306	12/02/2024	ER25-657-000	Informational Filing of June 1, 2024, to May 31, 2025, Formula Rate Annual Update of NorthWestern Corporation	Montana OATT, Attachment O, Formula Rate Protocols and Template

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

INFORMATION ON FORMULA RATES - Formula Rate Variances
If a respondent does not submit such filings then indicate in a footnote to the applicable Form 1 schedule where formula rate inputs differ from amounts reported in the Form 1. The footnote should provide a narrative description explaining how the "rate" (or billing) was derived if different from the reported amount in the Form 1. The footnote should explain amounts excluded from the ratebase or where labor or other allocation factors, operating expenses, or other items impacting formula rate inputs differ from amounts reported in Form 1 schedule amounts. Where the Commission has provided guidance on formula rate inputs, the specific proceeding should be noted in the footnote.
Line No.	PageNumberOfFormulaRateVariances Page No(s). (a)	ScheduleOfFormulaRateVariances Schedule (b)	ColumnOfFormulaRateVariances Column (c)	LineNumberOfFormulaRateVariances Line No. (d)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

IMPORTANT CHANGES DURING THE QUARTER/YEAR
Give particulars (details) concerning the matters indicated below. Make the statements explicit and precise, and number them in accordance with the inquiries. Each inquiry should be answered. Enter "none," "not applicable," or "NA" where applicable. If information which answers an inquiry is given elsewhere in the report, make a reference to the schedule in which it appears. Changes in and important additions to franchise rights: Describe the actual consideration given therefore and state from whom the franchise rights were acquired. If acquired without the payment of consideration, state that fact. Acquisition of ownership in other companies by reorganization, merger, or consolidation with other companies: Give names of companies involved, particulars concerning the transactions, name of the Commission authorizing the transaction, and reference to Commission authorization. Purchase or sale of an operating unit or system: Give a brief description of the property, and of the transactions relating thereto, and reference to Commission authorization, if any was required. Give date journal entries called for by the Uniform System of Accounts were submitted to the Commission. Important leaseholds (other than leaseholds for natural gas lands) that have been acquired or given, assigned or surrendered: Give effective dates, lengths of terms, names of parties, rents, and other condition. State name of Commission authorizing lease and give reference to such authorization. Important extension or reduction of transmission or distribution system: State territory added or relinquished and date operations began or ceased and give reference to Commission authorization, if any was required. State also the approximate number of customers added or lost and approximate annual revenues of each class of service. Each natural gas company must also state major new continuing sources of gas made available to it from purchases, development, purchase contract or otherwise, giving location and approximate total gas volumes available, period of contracts, and other parties to any such arrangements, etc. Obligations incurred as a result of issuance of securities or assumption of liabilities or guarantees including issuance of short-term debt and commercial paper having a maturity of one year or less. Give reference to FERC or State Commission authorization, as appropriate, and the amount of obligation or guarantee. Changes in articles of incorporation or amendments to charter: Explain the nature and purpose of such changes or amendments. State the estimated annual effect and nature of any important wage scale changes during the year. State briefly the status of any materially important legal proceedings pending at the end of the year, and the results of any such proceedings culminated during the year. Describe briefly any materially important transactions of the respondent not disclosed elsewhere in this report in which an officer, director, security holder reported on Pages 104 or 105 of the Annual Report Form No. 1, voting trustee, associated company or known associate of any of these persons was a party or in which any such person had a material interest. (Reserved.) If the important changes during the year relating to the respondent company appearing in the annual report to stockholders are applicable in every respect and furnish the data required by Instructions 1 to 11 above, such notes may be included on this page. Describe fully any changes in officers, directors, major security holders and voting powers of the respondent that may have occurred during the reporting period. In the event that the respondent participates in a cash management program(s) and its proprietary capital ratio is less than 30 percent please describe the significant events or transactions causing the proprietary capital ratio to be less than 30 percent, and the extent to which the respondent has amounts loaned or money advanced to its parent, subsidiary, or affiliated companies through a cash management program(s). Additionally, please describe plans, if any to regain at least a 30 percent proprietary ratio.

1) N/A
2) Holding Company Reorganization On January 1, 2024, we completed the second and final phase of the holding company reorganization. NorthWestern Corporation contributed the assets and liabilities of its South Dakota and Nebraska regulated utilities to NorthWestern Energy Public Service Corporation, and then distributed its equity interest in NorthWestern Energy Public Service Corporation and certain other subsidiaries to NorthWestern Energy Group, Inc., resulting in NorthWestern Corporation owning and operating the Montana regulated utility and NorthWestern Energy Public Service Corporation owning and operating the Nebraska and South Dakota utilities, each as a direct subsidiary of NorthWestern Energy Group, Inc
3) Acquisition of Energy West Montana Assets In July 2024, we entered into an Asset Purchase Agreement with Hope Utilities to acquire its Energy West natural gas utility distribution system and operations serving approximately 33,000 customers located near Great Falls, Cut Bank, and West Yellowstone, Montana for approximately $39.0 million, subject to certain working capital and other agreed upon closing adjustments. The transaction is subject to a number of customary closing conditions, including MPSC approval, and we expect the acquisition to be completed in the first half of 2025. Colstrip - Puget Sound Energy Transaction In January 2023 and in July 2024, we entered into definitive agreements, the first with Avista Corporation (Avista) and the second with Puget Sound Energy (Puget), to acquire their respective interests in Colstrip Units 3 & 4 for $0. In particular, we agreed to acquire a 15% (222 megawatts) interest from Avista and a 25% (370 megawatts) interest from Puget. These agreements are substantially similar and are both scheduled to close December 31, 2025, subject to the satisfaction of customary closing conditions and approvals contained within the agreements. Under the terms of the agreements, we will be responsible for operating costs starting on January 1, 2026; while Puget and Avista will remain responsible for their respective pre-closing share of environmental and pension liabilities attributed to events or conditions existing prior to the closing of the transaction and for any future decommission and demolition costs associated with the existing facilities that comprise their interests. Acquisition of Avista and Puget's interests would result in our ownership of 55 percent of the facility with the ability to guide operating and maintenance investments. This would provide capacity to help us meet our obligation to provide reliable and cost effective power to our customers in Montana, while allowing opportunity for us to identify and plan for newer lower or no-carbon technologies in the future.
4) None.
5) None.
6) See Note 11 "Unsecured Credit Facilities" FERC Order ES23-53-000 and MPSC Order Number 7091 Docket Number D2023.07.062.
7) None.
8) None.
9) See Note 18, "Commitments and Contingencies".
10) None.
12) None.
13) On September 3rd, 2024, Cyndee Fang, Vice President of Regulatory Affiars, left the Company.
14) N/A.

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

COMPARATIVE BALANCE SHEET (ASSETS AND OTHER DEBITS)
Line No.	Title of Account (a)	Ref. Page No. (b)	Current Year End of Quarter/Year Balance (c)	Prior Year End Balance 12/31 (d)
1	UtilityPlantAbstract UTILITY PLANT
2	UtilityPlant Utility Plant (101-106, 114)	200	7,136,721,129	7,983,112,655
3	ConstructionWorkInProgress Construction Work in Progress (107)	200	125,080,799	358,401,452
4	UtilityPlantAndConstructionWorkInProgress TOTAL Utility Plant (Enter Total of lines 2 and 3)		7,261,801,927	8,341,514,107
5	AccumulatedProvisionForDepreciationAmortizationAndDepletionOfPlantUtility (Less) Accum. Prov. for Depr. Amort. Depl. (108, 110, 111, 115)	200	2,449,906,491	2,874,902,417
6	UtilityPlantNet Net Utility Plant (Enter Total of line 4 less 5)		4,811,895,436	5,466,611,690
7	NuclearFuelInProcessOfRefinementConversionEnrichmentAndFabrication Nuclear Fuel in Process of Ref., Conv., Enrich., and Fab. (120.1)	202
8	NuclearFuelMaterialsAndAssembliesStockAccountMajorOnly Nuclear Fuel Materials and Assemblies-Stock Account (120.2)
9	NuclearFuelAssembliesInReactorMajorOnly Nuclear Fuel Assemblies in Reactor (120.3)
10	SpentNuclearFuelMajorOnly Spent Nuclear Fuel (120.4)
11	NuclearFuelUnderCapitalLeases Nuclear Fuel Under Capital Leases (120.6)
12	AccumulatedProvisionForAmortizationOfNuclearFuelAssemblies (Less) Accum. Prov. for Amort. of Nucl. Fuel Assemblies (120.5)	202
13	NuclearFuelNet Net Nuclear Fuel (Enter Total of lines 7-11 less 12)
14	UtilityPlantAndNuclearFuelNet Net Utility Plant (Enter Total of lines 6 and 13)		4,811,895,437	5,466,611,690
15	OtherElectricPlantAdjustments Utility Plant Adjustments (116)		263,806,234	357,585,527
16	GasStoredUndergroundNoncurrent Gas Stored Underground - Noncurrent (117)		38,192,545	36,212,426
17	OtherPropertyAndInvestmentsAbstract OTHER PROPERTY AND INVESTMENTS
18	NonutilityProperty Nonutility Property (121)		686,805	686,805
19	AccumulatedProvisionForDepreciationAndAmortizationOfNonutilityProperty (Less) Accum. Prov. for Depr. and Amort. (122)		68,042	67,635
20	InvestmentInAssociatedCompanies Investments in Associated Companies (123)
21	InvestmentInSubsidiaryCompanies Investment in Subsidiary Companies (123.1)	224	16,896,016	33,374,273
23	NoncurrentPortionOfAllowances Noncurrent Portion of Allowances	228
24	OtherInvestments Other Investments (124)		14,135,821	13,050,811
25	SinkingFunds Sinking Funds (125)
26	DepreciationFund Depreciation Fund (126)
27	AmortizationFundFederal Amortization Fund - Federal (127)
28	OtherSpecialFunds Other Special Funds (128)
29	SpecialFunds Special Funds (Non Major Only) (129)
30	DerivativeInstrumentAssetsLongTerm Long-Term Portion of Derivative Assets (175)
31	DerivativeInstrumentAssetsHedgesLongTerm Long-Term Portion of Derivative Assets - Hedges (176)
32	OtherPropertyAndInvestments TOTAL Other Property and Investments (Lines 18-21 and 23-31)		31,650,599	47,044,254
33	CurrentAndAccruedAssetsAbstract CURRENT AND ACCRUED ASSETS
34	CashAndWorkingFunds Cash and Working Funds (Non-major Only) (130)
35	Cash Cash (131)		888,205	8,740,865
36	SpecialDeposits Special Deposits (132-134)		13,894,365	14,856,653
37	WorkingFunds Working Fund (135)		17,500	22,850
38	TemporaryCashInvestments Temporary Cash Investments (136)
39	NotesReceivable Notes Receivable (141)
40	CustomerAccountsReceivable Customer Accounts Receivable (142)		66,518,761	91,004,512
41	OtherAccountsReceivable Other Accounts Receivable (143)		12,617,308	17,049,224
42	AccumulatedProvisionForUncollectibleAccountsCredit (Less) Accum. Prov. for Uncollectible Acct.-Credit (144)		2,160,945	2,813,091
43	NotesReceivableFromAssociatedCompanies Notes Receivable from Associated Companies (145)
44	AccountsReceivableFromAssociatedCompanies Accounts Receivable from Assoc. Companies (146)		4,946,575	615,046
45	FuelStock Fuel Stock (151)	227	2,248,613	9,710,818
46	FuelStockExpensesUndistributed Fuel Stock Expenses Undistributed (152)	227
47	Residuals Residuals (Elec) and Extracted Products (153)	227
48	PlantMaterialsAndOperatingSupplies Plant Materials and Operating Supplies (154)	227	79,780,714	85,254,493
49	Merchandise Merchandise (155)	227
50	OtherMaterialsAndSupplies Other Materials and Supplies (156)	227
51	NuclearMaterialsHeldForSale Nuclear Materials Held for Sale (157)	202/227
52	AllowanceInventoryAndWithheld Allowances (158.1 and 158.2)	228
53	NoncurrentPortionOfAllowances (Less) Noncurrent Portion of Allowances	228
54	StoresExpenseUndistributed Stores Expense Undistributed (163)	227
55	GasStoredCurrent Gas Stored Underground - Current (164.1)		6,743,589	18,814,211
56	LiquefiedNaturalGasStoredAndHeldForProcessing Liquefied Natural Gas Stored and Held for Processing (164.2-164.3)
57	Prepayments Prepayments (165)		18,978,349	(a) 21,740,289
58	AdvancesForGas Advances for Gas (166-167)
59	InterestAndDividendsReceivable Interest and Dividends Receivable (171)
60	RentsReceivable Rents Receivable (172)		64,160	73,787
61	AccruedUtilityRevenues Accrued Utility Revenues (173)		74,104,042	105,109,956
62	MiscellaneousCurrentAndAccruedAssets Miscellaneous Current and Accrued Assets (174)		1,025,532	876,036
63	DerivativeInstrumentAssets Derivative Instrument Assets (175)
64	DerivativeInstrumentAssetsLongTerm (Less) Long-Term Portion of Derivative Instrument Assets (175)
65	DerivativeInstrumentAssetsHedges Derivative Instrument Assets - Hedges (176)
66	DerivativeInstrumentAssetsHedgesLongTerm (Less) Long-Term Portion of Derivative Instrument Assets - Hedges (176)
67	CurrentAndAccruedAssets Total Current and Accrued Assets (Lines 34 through 66)		279,666,769	371,055,649
68	DeferredDebitsAbstract DEFERRED DEBITS
69	UnamortizedDebtExpense Unamortized Debt Expenses (181)		9,376,139	(b) 11,096,631
70	ExtraordinaryPropertyLosses Extraordinary Property Losses (182.1)	230a
71	UnrecoveredPlantAndRegulatoryStudyCosts Unrecovered Plant and Regulatory Study Costs (182.2)	230b
72	OtherRegulatoryAssets Other Regulatory Assets (182.3)	232	676,869,364	746,025,553
73	PreliminarySurveyAndInvestigationCharges Prelim. Survey and Investigation Charges (Electric) (183)			376,264
74	PreliminaryNaturalGasSurveyAndInvestigationChargesAndOtherPreliminarySurveyAndInvestigationCharges Preliminary Natural Gas Survey and Investigation Charges 183.1)
75	OtherPreliminarySurveyAndInvestigationCharges Other Preliminary Survey and Investigation Charges (183.2)
76	ClearingAccounts Clearing Accounts (184)			2,522
77	TemporaryFacilities Temporary Facilities (185)
78	MiscellaneousDeferredDebits Miscellaneous Deferred Debits (186)	233	930,479	11,084,645
79	DeferredLossesFromDispositionOfUtilityPlant Def. Losses from Disposition of Utility Plt. (187)
80	ResearchDevelopmentAndDemonstrationExpenditures Research, Devel. and Demonstration Expend. (188)	352
81	UnamortizedLossOnReacquiredDebt Unamortized Loss on Reaquired Debt (189)		16,960,804	(c) 20,027,942
82	AccumulatedDeferredIncomeTaxes Accumulated Deferred Income Taxes (190)	234	194,013,891	289,883,014
83	UnrecoveredPurchasedGasCosts Unrecovered Purchased Gas Costs (191)		253,352	3,394,843
84	DeferredDebits Total Deferred Debits (lines 69 through 83)		898,404,029	1,081,886,370
85	AssetsAndOtherDebits TOTAL ASSETS (lines 14-16, 32, 67, and 84)		6,323,615,613	7,360,395,916

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

FOOTNOTE DATA

(a) Concept: Prepayments

Montana Operations Prepayments (165) are $11,230,070 for 2023.

(b) Concept: UnamortizedDebtExpense

Montana Operations Unamortized Debt Expenses (181) is $9,617,259 for 2023.

Montana Operations Unamortized Loss on Reacquired Debt (189) is $18,539,713 for 2023.

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

COMPARATIVE BALANCE SHEET (LIABILITIES AND OTHER CREDITS)
Line No.	Title of Account (a)	Ref. Page No. (b)	Current Year End of Quarter/Year Balance (c)	Prior Year End Balance 12/31 (d)
1	ProprietaryCapitalAbstract PROPRIETARY CAPITAL
2	CommonStockIssued Common Stock Issued (201)	250	1	1
3	PreferredStockIssued Preferred Stock Issued (204)	250	0
4	CapitalStockSubscribed Capital Stock Subscribed (202, 205)
5	StockLiabilityForConversion Stock Liability for Conversion (203, 206)
6	PremiumOnCapitalStock Premium on Capital Stock (207)
7	OtherPaidInCapital Other Paid-In Capital (208-211)	253	2,044,999,693	1,981,122,791
8	InstallmentsReceivedOnCapitalStock Installments Received on Capital Stock (212)	252
9	DiscountOnCapitalStock (Less) Discount on Capital Stock (213)	254
10	CapitalStockExpense (Less) Capital Stock Expense (214)	254b
11	RetainedEarnings Retained Earnings (215, 215.1, 216)	118	351,876,746	810,816,636
12	UnappropriatedUndistributedSubsidiaryEarnings Unappropriated Undistributed Subsidiary Earnings (216.1)	118	2,801,118	1,503,684
13	ReacquiredCapitalStock (Less) Reacquired Capital Stock (217)	250
14	NoncorporateProprietorship Noncorporate Proprietorship (Non-major only) (218)
15	AccumulatedOtherComprehensiveIncome Accumulated Other Comprehensive Income (219)	122(a)(b)	5,383,393	(d) 5,513,000
16	ProprietaryCapital Total Proprietary Capital (lines 2 through 15)		2,388,691,929	(e) 2,784,922,744
17	LongTermDebtAbstract LONG-TERM DEBT
18	Bonds Bonds (221)	256	2,074,660,000	(f) 2,479,660,000
19	ReacquiredBonds (Less) Reacquired Bonds (222)	256
20	AdvancesFromAssociatedCompanies Advances from Associated Companies (223)	256
21	OtherLongTermDebt Other Long-Term Debt (224)	256	342,000,000	(g) 318,000,000
22	UnamortizedPremiumOnLongTermDebt Unamortized Premium on Long-Term Debt (225)
23	UnamortizedDiscountOnLongTermDebtDebit (Less) Unamortized Discount on Long-Term Debt-Debit (226)			6,538
24	LongTermDebt Total Long-Term Debt (lines 18 through 23)		2,416,660,000	2,797,653,462
25	OtherNoncurrentLiabilitiesAbstract OTHER NONCURRENT LIABILITIES
26	ObligationsUnderCapitalLeaseNoncurrent Obligations Under Capital Leases - Noncurrent (227)		2,292,287	5,996,448
27	AccumulatedProvisionForPropertyInsurance Accumulated Provision for Property Insurance (228.1)
28	AccumulatedProvisionForInjuriesAndDamages Accumulated Provision for Injuries and Damages (228.2)		5,427,889	(h) 6,745,658
29	AccumulatedProvisionForPensionsAndBenefits Accumulated Provision for Pensions and Benefits (228.3)		4,015,920	(i) 4,631,028
30	AccumulatedMiscellaneousOperatingProvisions Accumulated Miscellaneous Operating Provisions (228.4)		30,772,444	50,272,082
31	AccumulatedProvisionForRateRefunds Accumulated Provision for Rate Refunds (229)
32	LongTermPortionOfDerivativeInstrumentLiabilities Long-Term Portion of Derivative Instrument Liabilities
33	LongTermPortionOfDerivativeInstrumentLiabilitiesHedges Long-Term Portion of Derivative Instrument Liabilities - Hedges
34	AssetRetirementObligations Asset Retirement Obligations (230)		33,987,819	41,424,213
35	OtherNoncurrentLiabilities Total Other Noncurrent Liabilities (lines 26 through 34)		68,464,519	109,069,429
36	CurrentAndAccruedLiabilitiesAbstract CURRENT AND ACCRUED LIABILITIES
37	NotesPayable Notes Payable (231)
38	AccountsPayable Accounts Payable (232)		(a) 90,053,114	131,709,370
39	NotesPayableToAssociatedCompanies Notes Payable to Associated Companies (233)
40	AccountsPayableToAssociatedCompanies Accounts Payable to Associated Companies (234)		2,928,190	4,804,188
41	CustomerDeposits Customer Deposits (235)		17,640,442	11,954,099
42	TaxesAccrued Taxes Accrued (236)	262	(b) 76,961,039	75,992,477
43	InterestAccrued Interest Accrued (237)		24,578,517	24,775,303
44	DividendsDeclared Dividends Declared (238)
45	MaturedLongTermDebt Matured Long-Term Debt (239)
46	MaturedInterest Matured Interest (240)
47	TaxCollectionsPayable Tax Collections Payable (241)		298,173	1,789,013
48	MiscellaneousCurrentAndAccruedLiabilities Miscellaneous Current and Accrued Liabilities (242)		(c) 57,584,644	(j) 73,408,287
49	ObligationsUnderCapitalLeasesCurrent Obligations Under Capital Leases-Current (243)		3,902,892	3,720,377
50	DerivativesInstrumentLiabilities Derivative Instrument Liabilities (244)
51	LongTermPortionOfDerivativeInstrumentLiabilities (Less) Long-Term Portion of Derivative Instrument Liabilities
52	DerivativeInstrumentLiabilitiesHedges Derivative Instrument Liabilities - Hedges (245)
53	LongTermPortionOfDerivativeInstrumentLiabilitiesHedges (Less) Long-Term Portion of Derivative Instrument Liabilities-Hedges
54	CurrentAndAccruedLiabilities Total Current and Accrued Liabilities (lines 37 through 53)		273,947,011	328,153,114
55	DeferredCreditsAbstract DEFERRED CREDITS
56	CustomerAdvancesForConstruction Customer Advances for Construction (252)		123,249,058	(k) 107,470,505
57	AccumulatedDeferredInvestmentTaxCredits Accumulated Deferred Investment Tax Credits (255)	266	2,229,208	258,964
58	DeferredGainsFromDispositionOfUtilityPlant Deferred Gains from Disposition of Utility Plant (256)
59	OtherDeferredCredits Other Deferred Credits (253)	269	93,579,661	147,334,417
60	OtherRegulatoryLiabilities Other Regulatory Liabilities (254)	278	119,721,846	190,647,029
61	UnamortizedGainOnReacquiredDebt Unamortized Gain on Reacquired Debt (257)
62	AccumulatedDeferredIncomeTaxesAcceleratedAmortizationProperty Accum. Deferred Income Taxes-Accel. Amort.(281)	272
63	AccumulatedDeferredIncomeTaxesOtherProperty Accum. Deferred Income Taxes-Other Property (282)		601,179,098	663,637,584
64	AccumulatedDeferredIncomeTaxesOther Accum. Deferred Income Taxes-Other (283)		235,893,283	231,248,668
65	DeferredCredits Total Deferred Credits (lines 56 through 64)		1,175,852,154	1,340,597,167
66	LiabilitiesAndOtherCredits TOTAL LIABILITIES AND STOCKHOLDER EQUITY (lines 16, 24, 35, 54 and 65)		6,323,615,613	7,360,395,916

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

FOOTNOTE DATA

(a) Concept: AccountsPayable

Montana Operations unfunded reserves for Accounts Payable (232) are $1,774,369 and $2,120,217 for 2024 and 2023, respectively

(b) Concept: TaxesAccrued

Montana Operations unfunded reserves for Taxes Accrued (236) are $74,804,269 and $ 72,794,059 for 2024 and 2023, respectively.

Montana Operations unfunded reserve for Miscellaneous Current and Accrued Liabilities (242) are $27,081,196 and $20,948,018 for 2024 and 2023, respectively.

(d) Concept: AccumulatedOtherComprehensiveIncome

Montana Operations Accumulated Other Comprehensive Income (219) is $5,831,221 for 2023.

(e) Concept: ProprietaryCapital

Subsequent to the distribution of NorthWestern Corporation's equity ownership interest in NorthWestern Energy Public Service Corporation and certain other non-utility subsidiaries on January 1, 2024, the NorthWestern Corporation total proprietary capital was $2,214,722,701. As of January 1, 2024, this amount represents the total proprietary capital for Montana operations.

(f) Concept: Bonds

Montana Operations Bonds (221) is $1,999,660,000 for 2023.

(g) Concept: OtherLongTermDebt

Montana Operations Other Long Term Debt (224) is $264,000,000 for 2023.

(h) Concept: AccumulatedProvisionForInjuriesAndDamages

Montana Operations Provision for Injuries and Damages (228.2) are $6,302,791 for 2023.

(i) Concept: AccumulatedProvisionForPensionsAndBenefits

Montana Operations Accumulated Provision for Pensions and Benefits (228.3) are $1,308,934 for 2023.

(j) Concept: MiscellaneousCurrentAndAccruedLiabilities

Montana Operations Miscellaneous Current and Accrued Liabilities (242) are $61,018,856 for 2023.

(k) Concept: CustomerAdvancesForConstruction

Montana Operations Customer Advances for Construction (252) are $107,470,505 for 2023.

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

STATEMENT OF INCOME
Quarterly Report in column (c) the current year to date balance. Column (c) equals the total of adding the data in column (g) plus the data in column (i) plus the data in column (k). Report in column (d) similar data for the previous year. This information is reported in the annual filing only. Enter in column (e) the balance for the reporting quarter and in column (f) the balance for the same three month period for the prior year. Report in column (g) the quarter to date amounts for electric utility function; in column (i) the quarter to date amounts for gas utility, and in column (k) the quarter to date amounts for other utility function for the current year quarter. Report in column (h) the quarter to date amounts for electric utility function; in column (j) the quarter to date amounts for gas utility, and in column (l) the quarter to date amounts for other utility function for the prior year quarter. If additional columns are needed, place them in a footnote. Annual or Quarterly if applicable Do not report fourth quarter data in columns (e) and (f) Report amounts for accounts 412 and 413, Revenues and Expenses from Utility Plant Leased to Others, in another utility column in a similar manner to a utility department. Spread the amount(s) over Lines 2 thru 26 as appropriate. Include these amounts in columns (c) and (d) totals. Report amounts in account 414, Other Utility Operating Income, in the same manner as accounts 412 and 413 above. Use page 122 for important notes regarding the statement of income for any account thereof. Give concise explanations concerning unsettled rate proceedings where a contingency exists such that refunds of a material amount may need to be made to the utility's customers or which may result in material refund to the utility with respect to power or gas purchases. State for each year effected the gross revenues or costs to which the contingency relates and the tax effects together with an explanation of the major factors which affect the rights of the utility to retain such revenues or recover amounts paid with respect to power or gas purchases. Give concise explanations concerning significant amounts of any refunds made or received during the year resulting from settlement of any rate proceeding affecting revenues received or costs incurred for power or gas purchases, and a summary of the adjustments made to balance sheet, income, and expense accounts. If any notes appearing in the report to stockholders are applicable to the Statement of Income, such notes may be included at page 122. Enter on page 122 a concise explanation of only those changes in accounting methods made during the year which had an effect on net income, including the basis of allocations and apportionments from those used in the preceding year. Also, give the appropriate dollar effect of such changes. Explain in a footnote if the previous year's/quarter's figures are different from that reported in prior reports. If the columns are insufficient for reporting additional utility departments, supply the appropriate account titles report the information in a footnote to this schedule.
Line No.	Title of Account (a)	(Ref.) Page No. (b)	Total Current Year to Date Balance for Quarter/Year (c)	Total Prior Year to Date Balance for Quarter/Year (d)	Current 3 Months Ended - Quarterly Only - No 4th Quarter (e)	Prior 3 Months Ended - Quarterly Only - No 4th Quarter (f)	Electric Utility Current Year to Date (in dollars) (g)	Electric Utility Previous Year to Date (in dollars) (h)	Gas Utiity Current Year to Date (in dollars) (i)	Gas Utility Previous Year to Date (in dollars) (j)	Other Utility Current Year to Date (in dollars) (k)	Other Utility Previous Year to Date (in dollars) (l)
1	UtilityOperatingIncomeAbstract UTILITY OPERATING INCOME
2	OperatingRevenues Operating Revenues (400)	300	1,234,008,163	1,658,678,800			1,027,480,707	1,282,105,235	205,531,424	375,425,391	996,032	1,148,174
3	OperatingExpensesAbstract Operating Expenses
4	OperationExpense Operation Expenses (401)	320	601,729,005	890,436,496			498,891,273	646,055,016	102,019,130	243,441,581	818,602	939,899
5	MaintenanceExpense Maintenance Expenses (402)	320	48,036,864	56,287,320			40,796,831	47,406,239	7,221,122	8,848,386	18,911	32,695
6	DepreciationExpense Depreciation Expense (403)	336	147,931,740	179,851,232			125,039,639	149,308,812	22,846,012	29,655,013	46,089	40,901
7	DepreciationExpenseForAssetRetirementCosts Depreciation Expense for Asset Retirement Costs (403.1)	336
8	AmortizationAndDepletionOfUtilityPlant Amort. & Depl. of Utility Plant (404-405)	336	15,745,292	15,879,321			8,776,685	9,619,264	6,968,607	6,260,057
9	AmortizationOfElectricPlantAcquisitionAdjustments Amort. of Utility Plant Acq. Adj. (406)	336	14,747,883	15,101,772			14,747,883	15,948,277	0	0
10	AmortizationOfPropertyLossesUnrecoveredPlantAndRegulatoryStudyCosts Amort. Property Losses, Unrecov Plant and Regulatory Study Costs (407)
11	AmortizationOfConversionExpenses Amort. of Conversion Expenses (407.2)
12	RegulatoryDebits Regulatory Debits (407.3)		39,840,684	83,200,914			27,630,970	53,116,240	12,209,714	30,084,675
13	RegulatoryCredits (Less) Regulatory Credits (407.4)		83,044,374	45,339,571			57,321,723	25,928,597	25,722,651	19,410,974
14	TaxesOtherThanIncomeTaxesUtilityOperatingIncome Taxes Other Than Income Taxes (408.1)	262	164,247,932	163,049,808			127,004,398	126,571,887	37,198,187	36,431,466	45,347	46,455
15	IncomeTaxesOperatingIncome Income Taxes - Federal (409.1)	262	1,904,817	3,150,973			397,921	4,010,306	1,521,370	7,183,190	14,474	21,911
16	IncomeTaxesUtilityOperatingIncomeOther Income Taxes - Other (409.1)	262	916,223	2,335,146			385,059	429,564	536,153	2,772,263	4,989	7,553
17	ProvisionsForDeferredIncomeTaxesUtilityOperatingIncome Provision for Deferred Income Taxes (410.1)	234, 272	319,664,736	301,078,323			241,322,245	219,290,850	78,358,682	81,799,417	16,191	11,944
18	ProvisionForDeferredIncomeTaxesCreditOperatingIncome (Less) Provision for Deferred Income Taxes-Cr. (411.1)	234, 272	303,691,475	290,267,630			222,335,142	212,486,809	81,356,333	77,780,820
19	InvestmentTaxCreditAdjustments Investment Tax Credit Adj. - Net (411.4)	266	1,970,244	129,483			1,970,244	129,482
20	GainsFromDispositionOfPlant (Less) Gains from Disp. of Utility Plant (411.6)
21	LossesFromDispositionOfServiceCompanyPlant Losses from Disp. of Utility Plant (411.7)
22	GainsFromDispositionOfAllowances (Less) Gains from Disposition of Allowances (411.8)
23	LossesFromDispositionOfAllowances Losses from Disposition of Allowances (411.9)
24	AccretionExpense Accretion Expense (411.10)
25	UtilityOperatingExpenses TOTAL Utility Operating Expenses (Enter Total of lines 4 thru 24)		964,357,491	1,363,662,383			805,740,323	1,033,211,567	157,684,947	329,373,348	932,221	1,077,470
27	NetUtilityOperatingIncome Net Util Oper Inc (Enter Tot line 2 less 25)		269,650,672	295,016,417			221,740,384	248,893,668	47,846,477	46,052,043	63,811	70,704
28	OtherIncomeAndDeductionsAbstract Other Income and Deductions
29	OtherIncomeAbstract Other Income
30	NonutilityOperatingIncomeAbstract Nonutilty Operating Income
31	RevenuesFromMerchandisingJobbingAndContractWork Revenues From Merchandising, Jobbing and Contract Work (415)		574,229	572,017
32	CostsAndExpensesOfMerchandisingJobbingAndContractWork (Less) Costs and Exp. of Merchandising, Job. & Contract Work (416)		465,686	198,753
33	RevenuesFromNonutilityOperations Revenues From Nonutility Operations (417)		84,271	166,027
34	ExpensesOfNonutilityOperations (Less) Expenses of Nonutility Operations (417.1)		167,477	513,794
35	NonoperatingRentalIncome Nonoperating Rental Income (418)
36	EquityInEarningsOfSubsidiaryCompanies Equity in Earnings of Subsidiary Companies (418.1)	119	1,443,963	1,281,354
37	InterestAndDividendIncome Interest and Dividend Income (419)		3,540	437,731
38	AllowanceForOtherFundsUsedDuringConstruction Allowance for Other Funds Used During Construction (419.1)		17,537,612	17,612,998
39	MiscellaneousNonoperatingIncome Miscellaneous Nonoperating Income (421)		637,335	78,654
40	GainOnDispositionOfProperty Gain on Disposition of Property (421.1)
41	OtherIncome TOTAL Other Income (Enter Total of lines 31 thru 40)		16,591,319	16,873,526
42	OtherIncomeDeductionsAbstract Other Income Deductions
43	LossOnDispositionOfProperty Loss on Disposition of Property (421.2)
44	MiscellaneousAmortization Miscellaneous Amortization (425)
45	Donations Donations (426.1)		732,306	1,009,410
46	LifeInsurance Life Insurance (426.2)
47	Penalties Penalties (426.3)		2,249,995	3,196
48	ExpendituresForCertainCivicPoliticalAndRelatedActivities Exp. for Certain Civic, Political & Related Activities (426.4)		200,297	377,026
49	OtherDeductions Other Deductions (426.5)		761,637	1,589,981
50	OtherIncomeDeductions TOTAL Other Income Deductions (Total of lines 43 thru 49)		555,755	2,979,613
51	TaxesApplicableToOtherIncomeAndDeductionsAbstract Taxes Applic. to Other Income and Deductions
52	TaxesOtherThanIncomeTaxesOtherIncomeAndDeductions Taxes Other Than Income Taxes (408.2)	262	2,856	1,550,307
53	IncomeTaxesFederal Income Taxes-Federal (409.2)	262	2,938,964	2,971,276
54	IncomeTaxesOther Income Taxes-Other (409.2)	262	810,080	350,353
55	ProvisionForDeferredIncomeTaxesOtherIncomeAndDeductions Provision for Deferred Inc. Taxes (410.2)	234, 272	(a) 12,137	6,770,585
56	ProvisionForDeferredIncomeTaxesCreditOtherIncomeAndDeductions (Less) Provision for Deferred Income Taxes-Cr. (411.2)	234, 272	18,228	10,905,042
57	InvestmentTaxCreditAdjustmentsNonutilityOperations Investment Tax Credit Adj.-Net (411.5)
58	InvestmentTaxCredits (Less) Investment Tax Credits (420)
59	TaxesOnOtherIncomeAndDeductions TOTAL Taxes on Other Income and Deductions (Total of lines 52-58)		3,745,809	2,363,135
60	NetOtherIncomeAndDeductions Net Other Income and Deductions (Total of lines 41, 50, 59)		13,401,265	16,257,048
61	InterestChargesAbstract Interest Charges
62	InterestOnLongTermDebt Interest on Long-Term Debt (427)		103,589,994	111,284,778
63	AmortizationOfDebtDiscountAndExpense Amort. of Debt Disc. and Expense (428)		1,459,646	1,952,407
64	AmortizationOfLossOnReacquiredDebt Amortization of Loss on Reaquired Debt (428.1)		1,563,112	2,576,003
65	AmortizationOfPremiumOnDebtCredit (Less) Amort. of Premium on Debt-Credit (429)
66	AmortizationOfGainOnReacquiredDebtCredit (Less) Amortization of Gain on Reaquired Debt-Credit (429.1)
67	InterestOnDebtToAssociatedCompanies Interest on Debt to Assoc. Companies (430)
68	OtherInterestExpense Other Interest Expense (431)		4,288,429	8,025,169
69	AllowanceForBorrowedFundsUsedDuringConstructionCredit (Less) Allowance for Borrowed Funds Used During Construction-Cr. (432)		7,927,686	6,696,447
70	NetInterestCharges Net Interest Charges (Total of lines 62 thru 69)		102,973,495	117,141,910
71	IncomeBeforeExtraordinaryItems Income Before Extraordinary Items (Total of lines 27, 60 and 70)		180,078,441	194,131,555
72	ExtraordinaryItemsAbstract Extraordinary Items
73	ExtraordinaryIncome Extraordinary Income (434)
74	ExtraordinaryDeductions (Less) Extraordinary Deductions (435)
75	NetExtraordinaryItems Net Extraordinary Items (Total of line 73 less line 74)
76	IncomeTaxesExtraordinaryItems Income Taxes-Federal and Other (409.3)	262
77	ExtraordinaryItemsAfterTaxes Extraordinary Items After Taxes (line 75 less line 76)
78	NetIncomeLoss Net Income (Total of line 71 and 77)		180,078,441	194,131,555

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

FOOTNOTE DATA

(a) Concept: ProvisionForDeferredIncomeTaxesOtherIncomeAndDeductions

Included in the Provision for Deferred Income Taxes, in the Statements of Income, is amortization of the excess and deficient ADIT's as follows:

Line No.	Description (a)	(b)	(c)	(d)	(e)	(f)	(g)	(h)	(i)	(j)	(k)

	FERC Method of Amortization	RSG	SL		ARAM/RSG	SL			SL (MT) / RSG (SD)	SL
	Amortization period	Book Lives	5 Years		Book Lives	5 Years			5 years (MT) / Book Lives (SD)	5 Years
	Protected/Unprotected	Protected	Unprotected		Protected	Unprotected			F/T "as-if" normalized	F/T "as-if" normalized
	FERC Amorization Account	410.1	410.1		411.1	411.1			411.1	410.1
	TCJA Excess ADIT Account Reduced	190	190	Subtotal	282	283	Subtotal	Total of 182.3	282	190
	Reg Asset Acccount Impacted	182.3	182.3	182.3	254	254	254	and 254	254	182.3	Total
1	Montana:
2	Electric	921,618	1,933,612	2,855,230	(4,180,225)	(1,245,191)	(5,425,416)	(2,570,186)	(4,912,312)	23,768	(7,458,730)
3	Gas	-	1,303,766	1,303,766	(562,558)	(1,191,518)	(1,754,076)	(450,310)	(1,415,705)	18,486	(1,847,529)
4	Subtotal	921,618	3,237,378	4,158,996	(4,742,783)	(2,436,709)	(7,179,492)	(3,020,496)	(6,328,017)	42,254	(9,306,259)

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

STATEMENT OF RETAINED EARNINGS
Do not report Lines 49-53 on the quarterly report. Report all changes in appropriated retained earnings, unappropriated retained earnings, and unappropriated undistributed subsidiary earnings for the year. Each credit and debit during the year should be identified as to the retained earnings account in which recorded (Accounts 433, 436-439 inclusive). Show the contra primary account affected in column (b). State the purpose and amount for each reservation or appropriation of retained earnings. List first Account 439, Adjustments to Retained Earnings, reflecting adjustments to the opening balance of retained earnings. Follow by credit, then debit items, in that order. Show dividends for each class and series of capital stock. Show separately the State and Federal income tax effect of items shown for Account 439, Adjustments to Retained Earnings. Explain in a footnote the basis for determining the amount reserved or appropriated. If such reservation or appropriation is to be recurrent, state the number and annual amounts to be reserved or appropriated as well as the totals eventually to be accumulated. If any notes appearing in the report to stockholders are applicable to this statement, attach them at page 122.
Line No.	Item (a)	Contra Primary Account Affected (b)	Current Quarter/Year Year to Date Balance (c)	Previous Quarter/Year Year to Date Balance (d)
	UnappropriatedRetainedEarningsAbstract UNAPPROPRIATED RETAINED EARNINGS (Account 216)
1	UnappropriatedRetainedEarnings Balance-Beginning of Period		810,816,636	769,493,168
2	ChangesAbstract Changes
3	AdjustmentsToRetainedEarningsAbstract Adjustments to Retained Earnings (Account 439)
4	AdjustmentsToRetainedEarningsCreditAbstract Adjustments to Retained Earnings Credit
4.1	AdjustmentsToRetainedEarningsCredit
9	AdjustmentsToRetainedEarningsCredit TOTAL Credits to Retained Earnings (Acct. 439)
10	AdjustmentsToRetainedEarningsDebitAbstract Adjustments to Retained Earnings Debit
10.1	AdjustmentsToRetainedEarningsDebit Holding Company Reorganization		570,525,446
15	AdjustmentsToRetainedEarningsDebit TOTAL Debits to Retained Earnings (Acct. 439)		570,525,446
16	BalanceTransferredFromIncome Balance Transferred from Income (Account 433 less Account 418.1)		181,522,404	195,412,909
17	AppropriationsOfRetainedEarningsAbstract Appropriations of Retained Earnings (Acct. 436)
22	AppropriationsOfRetainedEarnings TOTAL Appropriations of Retained Earnings (Acct. 436)
23	DividendsDeclaredPreferredStockAbstract Dividends Declared-Preferred Stock (Account 437)
29	DividendsDeclaredPreferredStock TOTAL Dividends Declared-Preferred Stock (Acct. 437)
30	DividendsDeclaredCommonStockAbstract Dividends Declared-Common Stock (Account 438)
30.1	DividendsDeclaredCommonStock		69,936,848	154,089,441
36	DividendsDeclaredCommonStock TOTAL Dividends Declared-Common Stock (Acct. 438)		69,936,848	154,089,441
37	TransfersFromUnappropriatedUndistributedSubsidiaryEarnings Transfers from Acct 216.1, Unapprop. Undistrib. Subsidiary Earnings
38	UnappropriatedRetainedEarnings Balance - End of Period (Total 1,9,15,16,22,29,36,37)		351,876,746	810,816,636
39	AppropriatedRetainedEarningsAbstract APPROPRIATED RETAINED EARNINGS (Account 215)
45	AppropriatedRetainedEarnings TOTAL Appropriated Retained Earnings (Account 215)
	AppropriatedRetainedEarningsAmortizationReserveFederalAbstract APPROP. RETAINED EARNINGS - AMORT. Reserve, Federal (Account 215.1)
46	AppropriatedRetainedEarningsAmortizationReserveFederal TOTAL Approp. Retained Earnings-Amort. Reserve, Federal (Acct. 215.1)
47	AppropriatedRetainedEarningsIncludingReserveAmortization TOTAL Approp. Retained Earnings (Acct. 215, 215.1) (Total 45,46)
48	RetainedEarnings TOTAL Retained Earnings (Acct. 215, 215.1, 216) (Total 38, 47) (216.1)		351,876,746	810,816,636
	UnappropriatedUndistributedSubsidiaryEarningsAbstract UNAPPROPRIATED UNDISTRIBUTED SUBSIDIARY EARNINGS (Account Report only on an Annual Basis, no Quarterly)
49	UnappropriatedUndistributedSubsidiaryEarnings Balance-Beginning of Year (Debit or Credit)		1,503,684	222,330
50	EquityInEarningsOfSubsidiaryCompanies Equity in Earnings for Year (Credit) (Account 418.1)		1,443,963	1,281,354
51	DividendsReceived (Less) Dividends Received (Debit)
52	ChangesUnappropriatedUndistributedSubsidiaryEarningsCredits TOTAL other Changes in unappropriated undistributed subsidiary earnings for the year
52.1	ChangesUnappropriatedUndistributedSubsidiaryEarningsCredits Other unappropriated undistributed subsidiary earnings		(a) 146,529
53	UnappropriatedUndistributedSubsidiaryEarnings Balance-End of Year (Total lines 49 thru 52)		2,801,118	1,503,684

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

FOOTNOTE DATA

(a) Concept: ChangesUnappropriatedUndistributedSubsidiaryEarningsCredits

Reclassification between Retained Earnings and Unappropriated Undistributed Subsidiary Earnings.

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

STATEMENT OF CASH FLOWS
Codes to be used:(a) Net Proceeds or Payments;(b)Bonds, debentures and other long-term debt; (c) Include commercial paper; and (d) Identify separately such items as investments, fixed assets, intangibles, etc. Information about noncash investing and financing activities must be provided in the Notes to the Financial statements. Also provide a reconciliation between "Cash and Cash Equivalents at End of Period" with related amounts on the Balance Sheet. Operating Activities - Other: Include gains and losses pertaining to operating activities only. Gains and losses pertaining to investing and financing activities should be reported in those activities. Show in the Notes to the Financials the amounts of interest paid (net of amount capitalized) and income taxes paid. Investing Activities: Include at Other (line 31) net cash outflow to acquire other companies. Provide a reconciliation of assets acquired with liabilities assumed in the Notes to the Financial Statements. Do not include on this statement the dollar amount of leases capitalized per the USofA General Instruction 20; instead provide a reconciliation of the dollar amount of leases capitalized with the plant cost.
Line No.	Description (See Instructions No.1 for explanation of codes) (a)	Current Year to Date Quarter/Year (b)	Previous Year to Date Quarter/Year (c)
1	NetCashFlowFromOperatingActivitiesAbstract Net Cash Flow from Operating Activities
2	NetIncomeLoss Net Income (Line 78(c) on page 117)	180,078,441	194,131,555
3	NoncashChargesCreditsToIncomeAbstract Noncash Charges (Credits) to Income:
4	DepreciationAndDepletion Depreciation and Depletion	147,931,740	179,851,232
5	NoncashAdjustmentsToCashFlowsFromOperatingActivities Amortization of (Specify) (footnote details)
5.1	NoncashAdjustmentsToCashFlowsFromOperatingActivitiesDescription Amortization of	30,493,175	30,981,093
5.2	NoncashAdjustmentsToCashFlowsFromOperatingActivitiesDescription Other Non-cash charges to net income-net	(a) 7,050,428	10,607,927
8	DeferredIncomeTaxesNet Deferred Income Taxes (Net)	15,967,170	6,676,236
9	InvestmentTaxCreditAdjustmentsNet Investment Tax Credit Adjustment (Net)	1,970,244	129,483
10	NetIncreaseDecreaseInReceivablesOperatingActivities Net (Increase) Decrease in Receivables	9,651,518	28,520,658
11	NetIncreaseDecreaseInInventoryOperatingActivities Net (Increase) Decrease in Inventory	6,710,218	7,177,502
12	NetIncreaseDecreaseInAllowancesInventoryOperatingActivities Net (Increase) Decrease in Allowances Inventory
13	NetIncreaseDecreaseInPayablesAndAccruedExpensesOperatingActivities Net Increase (Decrease) in Payables and Accrued Expenses	20,062,712	68,347,954
14	NetIncreaseDecreaseInOtherRegulatoryAssetsOperatingActivities Net (Increase) Decrease in Other Regulatory Assets	9,340,746	36,795,341
15	NetIncreaseDecreaseInOtherRegulatoryLiabilitiesOperatingActivities Net Increase (Decrease) in Other Regulatory Liabilities	35,364,509	19,246,127
16	AllowanceForOtherFundsUsedDuringConstructionOperatingActivities (Less) Allowance for Other Funds Used During Construction	17,537,612	17,612,998
17	UndistributedEarningsFromSubsidiaryCompaniesOperatingActivities (Less) Undistributed Earnings from Subsidiary Companies	1,443,963	1,281,354
18	OtherAdjustmentsToCashFlowsFromOperatingActivities Other (provide details in footnote):
18.1	OtherAdjustmentsToCashFlowsFromOperatingActivitiesDescription Other	(b) 30,242,813	79,899,767
22	NetCashFlowFromOperatingActivities Net Cash Provided by (Used in) Operating Activities (Total of Lines 2 thru 21)	334,134,984	494,723,353
24	CashFlowsFromInvestmentActivitiesAbstract Cash Flows from Investment Activities:
25	ConstructionAndAcquisitionOfPlantIncludingLandAbstract Construction and Acquisition of Plant (including land):
26	GrossAdditionsToUtilityPlantLessNuclearFuelInvestingActivities Gross Additions to Utility Plant (less nuclear fuel)	489,816,600	572,121,801
27	GrossAdditionsToNuclearFuelInvestingActivities Gross Additions to Nuclear Fuel
28	GrossAdditionsToCommonUtilityPlantInvestingActivities Gross Additions to Common Utility Plant	12,693,286	12,355,642
29	GrossAdditionsToNonutilityPlantInvestingActivities Gross Additions to Nonutility Plant
30	AllowanceForOtherFundsUsedDuringConstructionInvestingActivities (Less) Allowance for Other Funds Used During Construction	17,537,612	17,612,998
31	OtherConstructionAndAcquisitionOfPlantInvestmentActivities Other (provide details in footnote):
34	CashOutflowsForPlant Cash Outflows for Plant (Total of lines 26 thru 33)	484,972,274	566,864,445
36	AcquisitionOfOtherNoncurrentAssets Acquisition of Other Noncurrent Assets (d)
37	ProceedsFromDisposalOfNoncurrentAssets Proceeds from Disposal of Noncurrent Assets (d)
39	InvestmentsInAndAdvancesToAssociatedAndSubsidiaryCompanies Investments in and Advances to Assoc. and Subsidiary Companies
40	ContributionsAndAdvancesFromAssociatedAndSubsidiaryCompanies Contributions and Advances from Assoc. and Subsidiary Companies
41	DispositionOfInvestmentsInAndAdvancesToAssociatedAndSubsidiaryCompaniesAbstract Disposition of Investments in (and Advances to)
42	DispositionOfInvestmentsInAndAdvancesToAssociatedAndSubsidiaryCompanies Disposition of Investments in (and Advances to) Associated and Subsidiary Companies
44	PurchaseOfInvestmentSecurities Purchase of Investment Securities (a)
45	ProceedsFromSalesOfInvestmentSecurities Proceeds from Sales of Investment Securities (a)
46	LoansMadeOrPurchased Loans Made or Purchased
47	CollectionsOnLoans Collections on Loans
49	NetIncreaseDecreaseInReceivablesInvestingActivities Net (Increase) Decrease in Receivables
50	NetIncreaseDecreaseInInventoryInvestingActivities Net (Increase) Decrease in Inventory
51	NetIncreaseDecreaseInAllowancesHeldForSpeculationInvestingActivities Net (Increase) Decrease in Allowances Held for Speculation
52	NetIncreaseDecreaseInPayablesAndAccruedExpensesInvestingActivities Net Increase (Decrease) in Payables and Accrued Expenses
53	OtherAdjustmentsToCashFlowsFromInvestmentActivities Other (provide details in footnote):
53.1	OtherAdjustmentsToCashFlowsFromInvestmentActivitiesDescription Investment in Equity Securities	253,166	9,105,446
57	CashFlowsProvidedFromUsedInInvestmentActivities Net Cash Provided by (Used in) Investing Activities (Total of lines 34 thru 55)	485,225,440	575,969,891
59	CashFlowsFromFinancingActivitiesAbstract Cash Flows from Financing Activities:
60	ProceedsFromIssuanceAbstract Proceeds from Issuance of:
61	ProceedsFromIssuanceOfLongTermDebtFinancingActivities Long-Term Debt (b)	175,000,000	300,000,000
62	ProceedsFromIssuanceOfPreferredStockFinancingActivities Preferred Stock
63	ProceedsFromIssuanceOfCommonStockFinancingActivities Common Stock		73,612,936
64	OtherAdjustmentsToCashFlowsFromFinancingActivities Other (provide details in footnote):
64.1	OtherAdjustmentsToCashFlowsFromFinancingActivitiesDescription Treasury Stock Activity		731,249
66	NetIncreaseInShortTermDebt Net Increase in Short-Term Debt (c)
67	OtherAdjustmentsByOutsideSourcesToCashFlowsFromFinancingActivities Other (provide details in footnote):
67.1	DescriptionForOtherAdjustmentsByOutsideSourcesToCashFlowsFromFinancingActivities Other		92,403
67.2	DescriptionForOtherAdjustmentsByOutsideSourcesToCashFlowsFromFinancingActivities Distribution of Cash from NorthWestern Energy Group, Inc.	60,000,000
70	CashProvidedByOutsideSources Cash Provided by Outside Sources (Total 61 thru 69)	235,000,000	374,251,782
72	PaymentsForRetirementAbstract Payments for Retirement of:
73	PaymentsForRetirementOfLongTermDebtFinancingActivities Long-term Debt (b)	100,000,000
74	PaymentsForRetirementOfPreferredStockFinancingActivities Preferred Stock
75	PaymentsForRetirementOfCommonStockFinancingActivities Common Stock
76	OtherRetirementsOfBalancesImpactingCashFlowsFromFinancingActivities Other (provide details in footnote):
76.1	DescriptionOfOtherRetirementsImpactingCashFlowsFromFinancingActivities Debt Financing Costs	792,994	4,109,961
76.2	DescriptionOfOtherRetirementsImpactingCashFlowsFromFinancingActivities Line of Credit (Repayments) Borrowings, Net	78,000,000	132,000,000
76.3	DescriptionOfOtherRetirementsImpactingCashFlowsFromFinancingActivities Distribution of Cash to NorthWestern Public Service
78	NetDecreaseInShortTermDebt Net Decrease in Short-Term Debt (c)
80	DividendsOnPreferredStock Dividends on Preferred Stock
81	DividendsOnCommonStock Dividends on Common Stock	69,936,848	154,089,441
83	CashFlowsProvidedFromUsedInFinancingActivities Net Cash Provided by (Used in) Financing Activities (Total of lines 70 thru 81)	142,270,158	84,052,380
85	NetIncreaseDecreaseInCashAndCashEquivalentsAbstract Net Increase (Decrease) in Cash and Cash Equivalents
86	NetIncreaseDecreaseInCashAndCashEquivalents Net Increase (Decrease) in Cash and Cash Equivalents (Total of line 22, 57 and 83)	8,820,298	2,805,842
88	CashAndCashEquivalents Cash and Cash Equivalents at Beginning of Period	(c) 23,620,368	20,814,526
90	CashAndCashEquivalents Cash and Cash Equivalents at End of Period	14,800,070	(d) 23,620,368

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

FOOTNOTE DATA

(a) Concept: NoncashAdjustmentsToCashFlowsFromOperatingActivities

	12/31/2024	12/31/2023
Other Noncash Charges to Income, Net:
Amortization of debt issue costs, discount, and deferred hedge gain	3,233,304	5,500,328
Other noncash losses (gains)	(59,777)	(54,276)
Stock based compensation costs	3,876,901	5,161,875
	7,050,428	10,607,927

(b) Concept: OtherAdjustmentsToCashFlowsFromOperatingActivities

	12/31/2024	12/31/2023
Other Assets and Liabilities, Net:
Net change - other current assets	(7,893,558)	3,635,856
Net change - accrued utility revenues	9,990,207	12,308,528
Net change - deferred debits	2,980,620	95,975,764
Net change - deferred credits	(22,358,643)	(4,972,502)
Net change - noncurrent liabilities	(12,961,439)	(27,047,879)
	(30,242,813)	79,899,767

	12/31/2024	12/31/2023	12/31/2022
Cash (131)	888,205	8,740,865	8,029,111
Working Funds (135)	17,500	22,850	23,450
Other Special Deposits (134)	13,894,365	14,856,653	12,761,965
Total	14,800,070	23,620,368	20,814,526

(d) Concept: CashAndCashEquivalents

	12/31/2024	12/31/2023	12/31/2022
Cash (131)	888,205	8,740,865	8,029,111
Working Funds (135)	17,500	22,850	23,450
Other Special Deposits (134)	13,894,365	14,856,653	12,761,965
Total	14,800,070	23,620,368	20,814,526

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

NOTES TO FINANCIAL STATEMENTS

Use the space below for important notes regarding the Balance Sheet, Statement of Income for the year, Statement of Retained Earnings for the year, and Statement of Cash Flows, or any account thereof. Classify the notes according to each basic statement, providing a subheading for each statement except where a note is applicable to more than one statement.
Furnish particulars (details) as to any significant contingent assets or liabilities existing at end of year, including a brief explanation of any action initiated by the Internal Revenue Service involving possible assessment of additional income taxes of material amount, or of a claim for refund of income taxes of a material amount initiated by the utility. Give also a brief explanation of any dividends in arrears on cumulative preferred stock.
For Account 116, Utility Plant Adjustments, explain the origin of such amount, debits and credits during the year, and plan of disposition contemplated, giving references to Commission orders or other authorizations respecting classification of amounts as plant adjustments and requirements as to disposition thereof.
Where Accounts 189, Unamortized Loss on Reacquired Debt, and 257, Unamortized Gain on Reacquired Debt, are not used, give an explanation, providing the rate treatment given these items. See General Instruction 17 of the Uniform System of Accounts.
Give a concise explanation of any retained earnings restrictions and state the amount of retained earnings affected by such restrictions.
If the notes to financial statements relating to the respondent company appearing in the annual report to the stockholders are applicable and furnish the data required by instructions above and on pages 114-121, such notes may be included herein.
For the 3Q disclosures, respondent must provide in the notes sufficient disclosures so as to make the interim information not misleading. Disclosures which would substantially duplicate the disclosures contained in the most recent FERC Annual Report may be omitted.
For the 3Q disclosures, the disclosures shall be provided where events subsequent to the end of the most recent year have occurred which have a material effect on the respondent. Respondent must include in the notes significant changes since the most recently completed year in such items as: accounting principles and practices; estimates inherent in the preparation of the financial statements; status of long-term contracts; capitalization including significant new borrowings or modifications of existing financing agreements; and changes resulting from business combinations or dispositions. However were material contingencies exist, the disclosure of such matters shall be provided even though a significant change since year end may not have occurred.
Finally, if the notes to the financial statements relating to the respondent appearing in the annual report to the stockholders are applicable and furnish the data required by the above instructions, such notes may be included herein.

NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

(1) Nature of Operations and Basis of Consolidation

NorthWestern Corporation (NW Corp), a direct wholly-owned subsidiary of NorthWestern Energy Group, Inc., doing business as NorthWestern Energy, provides electricity and / or natural gas to approximately 627,900 customers in Montana and Yellowstone National Park. We have generated and distributed electricity and distributed natural gas in Montana since 2002.

The Financial Statements for the periods included herein have been prepared by NorthWestern Corporation (NorthWestern, we or us), pursuant to the rules and regulations of the Federal Energy Regulatory Commission (FERC) as set forth in its applicable Uniform System of Accounts and published accounting releases. The preparation of financial statements in conformity with the accounting requirements of the FERC as set forth in its applicable Uniform System of Accounts and published accounting releases requires management to make estimates and assumptions that may affect the reported amounts of assets, liabilities, revenues and expenses during the reporting period. Actual results could differ from those estimates. The accompanying Consolidated Financial Statements include our accounts together with those of our wholly and majority-owned or controlled subsidiaries. All intercompany balances and transactions have been eliminated from the Consolidated Financial Statements. Events occurring subsequent to December 31, 2024, have been evaluated as to their potential impact to the Consolidated Financial Statements through the date of issuance.

The following notes to the financials statements appear in Northwestern Corporation’s annual report to the shareholders and are prepared in conformity with GAAP. This report differs from GAAP due to FERC requiring the presentation of subsidiaries on the equity method of accounting, which differs from Accounting Standards Codification (ASC) 810, Consolidation. ASC 810 requires that all majority-owned subsidiaries be consolidated. The other significant differences consist of the following:

• Removal and decommissioning costs of generation, transmission and distribution assets are reflected in the Balance Sheets as a component of accumulated depreciation of $444.1 million and $523.7 million as of December 31, 2024 and December 31, 2023, respectively, in accordance with regulatory treatment as compared to regulatory liabilities for GAAP purposes;

• Goodwill is reflected in the Balance Sheets as a utility plant adjustments of $263.8 million as of December 31, 2024 and $357.6 million as of December 31, 2023, respectively, in accordance with regulatory treatment, as compared to goodwill for GAAP purposes (see Note 8);

• The write-down of plant values associated with the 2002 acquisition of the Montana operations is reflected in the Balance Sheets as a component of accumulated depreciation of $147.6 million for December 31, 2024 and December 31, 2023, respectively, in accordance with regulatory treatment as compared to plant for GAAP purposes;

• The current portion of gas stored underground is reflected in the Balance Sheets as current and accrued assets, as compared to inventory for GAAP purposes;

• Operating lease right of use assets are reflected in the Balance Sheets as capital leases of $0.7 million and $0.9 million as of December 31, 2024 and December 31, 2023, respectfully, in accordance with regulatory treatment, as compared to non-current assets for GAAP purposes;

• Operating lease liabilities are reflected in the Balance Sheets as current and long term obligations under capital leases of $0.7 million and $0.9 million as of December 31, 2024 and December 31, 2023, respectfully, in accordance with regulatory treatment, as compared to accrued expenses and long term liabilities for GAAP purposes;

• Unamortized debt expense is classified in the Balance Sheets as deferred debits in accordance with regulatory treatment, as compared to long-term debt for GAAP purposes;

• Current and long-term debt is classified in the Balance Sheets as all long-term debt in accordance with regulatory treatment, while current and long-term debt are presented separately for GAAP reporting;

• The current portion of the provision for injuries and damages and the expected insurance proceeds receivable related to the provision for injuries and damages are reported as a current liability for GAAP purposes, as compared to a non-current liability for FERC purposes;

• Accumulated deferred tax assets and liabilities are classified in the Balance Sheets as gross non-current deferred debits and credits, respectively, while GAAP presentation reflects a net non-current deferred tax liability;

• Stranded tax effects associated with the Tax Cuts and Jobs Act are included in accumulated other comprehensive income (AOCI) in accordance with regulatory treatment, while included in retained earnings for GAAP purposes;

• Uncertain tax positions related to temporary differences are classified in the Balance Sheets within the deferred tax accounts in accordance with regulatory treatment, as compared to other noncurrent liabilities for GAAP purposes. In addition, interest related to uncertain tax positions is recognized in interest expense in accordance with regulatory treatment, as compared to income tax expense for GAAP purposes;

• Net periodic benefit costs and net periodic post retirement benefit costs are reflected in operating expense for FERC purposes, as compared to the GAAP presentation, which reflects the current service costs component of the net periodic benefit costs in operating expenses and the other components outside of income from operations. In addition, only the service cost component of net periodic benefit cost is eligible for capitalization for GAAP purposes, as compared to the total net periodic benefit costs for FERC purposes;

• Regulatory assets and liabilities are reflected in the Balance Sheets as non-current items, while current and non-current amounts are presented separately for GAAP;

• Unbilled revenue is reflected in the Balance Sheets in Accrued utility revenues in accordance with regulatory treatment, as compared to Accounts receivable, net for GAAP purposes;

• Implementation costs associated with cloud computing arrangements are reflected on the Balance Sheets as Miscellaneous Intangible Plant in accordance with regulatory treatment, as compared to Other current assets for GAAP purposes. Additionally, these cash outflows are presented within investing activities cash outflows in the Statement of Cash Flows in accordance with regulatory treatment, as compared to operating activities cash outflows for GAAP purposes; and

• GAAP revenue differs from FERC revenue primarily due to the equity method of accounting as discussed above, netting of electric purchases and sales for resale in revenue for the GAAP presentation as compared to a gross presentation for FERC purposes (with the exception of those transactions in a regional transmission organization (RTO)), the netting of RTO transmission transactions for the GAAP presentation as compared to a gross presentation for FERC purposes, and the classification of regulatory amortizations in revenue for GAAP purposes as compared to expense for FERC purposes.

Events occurring subsequent to December 31, 2024, have been evaluated as to their potential impact to the Financial Statements through the date of this report.

Holding Company Reorganization

On October 2, 2023, NW Corp and NorthWestern Energy Group, Inc. completed a merger transaction pursuant to which NorthWestern Energy Group, Inc. became the holding company parent of NW Corp. In this reorganization, shareholders of NW Corp (the predecessor publicly held parent company) became shareholders of NorthWestern Energy Group, Inc., maintaining the same number of shares and ownership percentage as held in NW Corp immediately prior to the reorganization. NW Corp became a wholly-owned subsidiary of NorthWestern Energy Group, Inc. The transaction was effected pursuant to a merger pursuant to Section 251(g) of the General Corporation Law of the State of Delaware, which provides for the formation of a holding company without a vote of the shareholders of the constituent corporation. As a result of the reorganization, NorthWestern Energy Group, Inc. became the successor issuer to NW Corp pursuant to Rule 12g-3(a) of the Securities Exchange Act of 1934, and as a result, NorthWestern Energy Group, Inc.'s common stock was deemed registered under Section 12(b) of the Securities Exchange Act of 1934.

Upon the conversion of all issued and outstanding NW Corp common stock into common stock in NorthWestern Energy Group, Inc., as described above, the common stock of NW Corp ceased to exist. The accounting for this common stock conversion is treated as a retirement of common stock for NW Corp as the shares cease to exist. As such, the amounts included in Common stock and Treasury stock were cleared into Paid-in capital. Subsequent to the reorganization, NW Corp has 100 shares of common stock issued and outstanding, which are held by NorthWestern Energy Group, Inc.

On January 1, 2024, we completed the second and final phase of the holding company reorganization. NW Corp contributed the assets and liabilities of its South Dakota and Nebraska regulated utilities to NorthWestern Energy Public Service Corporation (NWE Public Service), and then distributed its equity interest in NWE Public Service and certain other subsidiaries to NorthWestern Energy Group, Inc., resulting in NW Corp owning and operating the Montana regulated utility and NWE Public Service owning and operating the Nebraska and South Dakota utilities, each as a direct subsidiary of NorthWestern Energy Group, Inc. Due to this reorganization, the financial position, results of operations, and cash flows of the South Dakota and Nebraska regulated utilities and certain other subsidiaries are reported in historical periods as discontinued operations. See Note 2 - Discontinued Operations for further information.

(2) Discontinued Operations

As described in Note 1 - Nature of Operations and Basis of Consolidation, on January 1, 2024, we completed the previously announced second and final phase of our holding company reorganization resulting in the distribution of our ownership in NWE Public Service, our formerly held South Dakota electric and natural gas and Nebraska natural gas regulated utility operations, and the equity ownership in certain non-regulated subsidiaries, to NorthWestern Energy Group, Inc. As a result of this distribution, the historical assets and liabilities for these operating segments have been classified as assets and liabilities of discontinued operations and the historical results of operations are shown in discontinued operations, net of tax. Our Financial Statements for prior periods reflect this reclassification. The notes to our financial statements present information from continuing operations.

The carrying amounts of the major classes of assets and liabilities of discontinued operations included in our Consolidated Balance Sheet at December 31, 2023, were as follows:

	As of December 31, 2023
ASSETS
Current Assets:
Cash and cash equivalents	$ 253
Restricted cash	1,166
Accounts receivable, net	37,547
Inventories	31,717
Regulatory assets	5,681
Prepaid expenses and other	10,910
Total current assets	87,274
Property, plant, and equipment, net	1,067,606
Goodwill	93,779
Regulatory assets	93,933
Other noncurrent assets	21,555
Total Assets	$ 1,364,147
LIABILITIES
Current Liabilities:
Accounts payable	28,766
Accrued expenses	27,949
Regulatory liabilities	20,767
Total current liabilities	77,482
Long-term debt	532,148
Deferred income taxes	20,307
Noncurrent regulatory liabilities	106,307
Other noncurrent liabilities	57,205
Total Liabilities	$ 793,449
Net Assets	$ 570,698

The reconciliation of the major classes of income and expense constituting pretax income from discontinued operations to the after-tax income from discontinued operations on the Condensed Consolidated Statements of Income were as follows:

	Year Ended December 31, 2023
Operating revenues	$ 285,942
Operating expenses	249,024
Operating Income	36,918
Interest expense, net	(22,221)
Other income, net	1,805
Income from discontinued operations before income tax	16,502
Income tax expense	6,855
Discontinued operations, net of tax	$ 23,357

(3) Significant Accounting Policies

Use of Estimates

The preparation of financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the Consolidated Financial Statements and the reported amounts of revenues and expenses during the reporting period. Estimates are used for such items as long-lived asset values and impairment charges, long-lived asset useful lives, tax provisions, uncertain tax position reserves, AROs, regulatory assets and liabilities, allowances for uncollectible accounts, our QF liability, environmental liabilities, unbilled revenues and actuarially determined benefit costs and liabilities. We revise the recorded estimates when we receive better information or when we can determine actual amounts. Those revisions can affect operating results.

Revenue Recognition

The Company recognizes revenue as customers obtain control of promised goods and services in an amount that reflects consideration expected in exchange for those goods or services. Generally, the delivery of electricity and natural gas results in the transfer of control to customers at the time the commodity is delivered and the amount of revenue recognized is equal to the amount billed to each customer, including estimated volumes delivered when billings have not yet occurred.

Cash Equivalents

We consider all highly liquid investments with maturities of three months or less at the time of purchase to be cash equivalents.

Restricted Cash

Restricted cash consists primarily of funds held in trust accounts to satisfy the requirements of certain stipulation agreements and insurance reserve requirements.

Accounts Receivable, Net

Accounts receivable are net of allowances for uncollectible accounts of $2.2 million and $2.5 million at December 31, 2024 and December 31, 2023, respectively. Receivables include unbilled revenues of $74.1 million and $84.1 million at December 31, 2024 and December 31, 2023, respectively.

Regulation of Utility Operations

Our regulated operations are subject to the provisions of ASC 980, Regulated Operations. Regulated accounting is appropriate provided that (i) rates are established by or subject to approval by independent, third-party regulators, (ii) rates are designed to recover the specific enterprise's cost of service, and (iii) in view of demand for service, it is reasonable to assume that rates are set at levels that will recover costs and can be charged to and collected from customers.

Our Consolidated Financial Statements reflect the effects of the different rate making principles followed by the jurisdictions regulating us. The economic effects of regulation can result in regulated companies recording costs that have been, or are deemed probable to be, allowed in the ratemaking process in a period different from the period in which the costs would be charged to expense by an unregulated enterprise. When this occurs, costs are deferred as regulatory assets and recorded as expenses in the periods when those same amounts are reflected in rates. Additionally, regulators can impose liabilities upon a regulated company for amounts previously collected from customers and for amounts that are expected to be refunded to customers (regulatory liabilities).

If we were required to terminate the application of these provisions to our regulated operations, all such deferred amounts would be recognized in the Consolidated Statements of Income at that time. This would result in a charge to earnings and accumulated other comprehensive loss (AOCL), net of applicable income taxes, which could be material. In addition, we would determine any impairment to the carrying costs of deregulated plant and inventory assets.

Derivative Financial Instruments

We account for derivative instruments in accordance with ASC 815, Derivatives and Hedging. All derivatives are recognized in the Consolidated Balance Sheets at their fair value unless they qualify for certain exceptions, including the normal purchases and normal sales (NPNS) exception. Additionally, derivatives that qualify and are designated for hedge accounting are classified as either hedges of the fair value of a recognized asset or liability or of an unrecognized firm commitment (fair-value hedge) or hedges of a forecasted transaction or the variability of cash flows to be received or paid related to a recognized asset or liability (cash-flow hedge). For fair-value hedges, changes in fair values for both the derivative and the underlying hedged exposure are recognized in earnings each period. For cash-flow hedges, the portion of the derivative gain or loss that is effective in offsetting the change in the cost or value of the underlying exposure is deferred in AOCL and later reclassified into earnings when the underlying transaction occurs. Gains and losses from the ineffective portion of any hedge are recognized in earnings immediately. For other derivative contracts that do not qualify or are not designated for hedge accounting, changes in the fair value of the derivatives are recognized in earnings each period. Cash inflows and outflows related to derivative instruments are included as a component of operating, investing or financing cash flows in the Consolidated Statements of Cash Flows, depending on the underlying nature of the hedged items. As of December 31, 2024, the only derivative instruments we have qualify for the NPNS exception.

Revenues and expenses on contracts that are designated as NPNS are recognized when the underlying physical transaction is completed. While these contracts are considered derivative financial instruments, they are not required to be recorded at fair value, but on an accrual basis of accounting. NPNS are contracts where physical delivery is probable, quantities are expected to be used or sold in the normal course of business over a reasonable period of time, and price is not tied to an unrelated underlying derivative. As part of our regulated electric and gas operations, we enter into contracts to buy and sell energy to meet the requirements of our customers. These contracts include short-term and long-term commitments to purchase and sell energy in the retail and wholesale markets with the intent and ability to deliver or take delivery. If it were determined that a transaction designated as a NPNS no longer met the exceptions, the fair value of the related contract would be reflected as an asset or liability and immediately recognized through earnings. See Note 9 - Risk Management and Hedging Activities, for further discussion of our derivative activity.

Property, Plant and Equipment

Property, plant and equipment are stated at original cost, including contracted services, direct labor and material, allowance for funds used during construction (AFUDC), and indirect charges for engineering, supervision and similar overhead items. All expenditures for maintenance and repairs of utility property, plant and equipment are charged to the appropriate maintenance expense accounts. A betterment or replacement of a unit of property is accounted for as an addition and retirement of utility plant. At the time of such a retirement, the accumulated provision for depreciation is charged with the original cost of the property retired and also for the net cost of removal. Also included in plant and equipment are assets under finance lease, which are stated at the present value of minimum lease payments.

AFUDC represents the cost of financing construction projects with borrowed funds and equity funds. While cash is not realized currently from such allowance, it is realized under the ratemaking process over the service life of the related property through increased revenues resulting from a higher rate base and higher depreciation expense. The component of AFUDC attributable to borrowed funds is included as a reduction to interest expense, while the equity component is included in other income. This rate averaged 7.0% and 6.4% for 2024 and 2023, respectively. AFUDC capitalized totaled $25.5 million and $23.1 million for the years ended December 31, 2024 and 2023, respectively.

We record provisions for depreciation at amounts substantially equivalent to calculations made on a straight-line method by applying various rates based on useful lives of the various classes of properties (ranging from 5 to 127 years) determined from engineering studies. As a percentage of the depreciable utility plant at the beginning of the year, our provision for depreciation of utility plant was approximately 2.8% for 2024 and 2023.

Depreciation rates include a provision for our share of the estimated costs to decommission our jointly owned plants at the end of the useful life. The annual provision for such costs is included in depreciation expense, while the accumulated provisions are included in noncurrent regulatory liabilities.

Pension and Postretirement Benefits

We have liabilities under defined benefit retirement plans and a postretirement plan that offers certain health care and life insurance benefits to eligible employees and their dependents. The costs of these plans are dependent upon numerous factors, assumptions and estimates, including determination of discount rate, expected return on plan assets, rate of future compensation increases, age and mortality and employment periods. In determining the projected benefit obligations and costs, assumptions can change from period to period and may result in material changes in the cost and liabilities we recognize.

Income Taxes

We follow the liability method in accounting for income taxes. Deferred income tax assets and liabilities represent the future effects on income taxes from temporary differences between the bases of assets and liabilities for financial reporting and tax purposes. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to reverse. The probability of realizing deferred tax assets is based on forecasts of future taxable income and the availability of tax planning strategies that can be implemented, if necessary, to realize deferred tax assets. We establish a valuation allowance when it is more likely than not that all, or a portion of, a deferred tax asset will not be realized.

Exposures exist related to various tax filing positions, which may require an extended period of time to resolve and may result in income tax adjustments by taxing authorities. We have reduced deferred tax assets or established liabilities based on our best estimate of future probable adjustments related to these exposures. On a quarterly basis, we evaluate exposures in light of any additional information and make adjustments as necessary to reflect the best estimate of the future outcomes. We believe our deferred tax assets and established liabilities are appropriate for estimated exposures; however, actual results may differ from these estimates. The resolution of tax matters in a particular future period could have a material impact on our Consolidated Income Statements and provision for income taxes.

Under the Inflation Reduction Act of 2022 our production tax credits may be transferred to an unrelated entity. Our policy is to account for these transferable credits within income tax expense.

Environmental Costs

We record environmental costs when it is probable we are liable for the costs and we can reasonably estimate the liability. If an environmental cost is related to facilities we currently use, such as pollution control equipment, then we may capitalize and depreciate the costs over the remaining life of the asset, assuming the costs are recoverable in future rates or future cash flows.

Our remediation cost estimates are based on the use of an environmental consultant, our experience, our assessment of the current situation and the technology currently available for use in the remediation. We regularly adjust the recorded costs as we revise estimates and as remediation proceeds. If we are one of several designated responsible parties, then we estimate and record only our share of the cost.

Supplemental Cash Flow Information

	Year Ended December 31,
	2024	2023
		(in thousands)
Cash paid (received) for:
Income taxes (1)	$ (4,769)	$ (827)
Interest (2)	100,853	105,238
Significant non-cash transactions:
Capital expenditures included in trade accounts payable (3)	18,537	42,322

(1) Includes income tax refunds from discontinued operations of $845 as of December 31, 2023.

(2) Includes interest payments from discontinued operations of $20,778 as of December 31, 2023.

(3) Includes capital expenditures included in trade accounts payable of discontinued operations of $3,867 as of December 31, 2023.

The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the Consolidated Balance Sheets that sum to the total of the same such amounts shown in the Consolidated Statements of Cash Flows (in thousands):

	December 31,
	2024	2023
Cash and cash equivalents	$ 1,934	$ 8,851
Restricted cash	13,894	14,857
Discontinued operations (Note 2)	—	1,419
Total cash, cash equivalents, and restricted cash shown in the Consolidated Statements of Cash Flows	$ 15,828	$ 25,127

Restricted cash consists primarily of funds held in trust accounts to satisfy the requirements of certain stipulation agreements and insurance reserve requirements.

Accounting Standards Issued

There were no accounting standards adopted in the current year that had a material impact to our financial condition, results of operations, and cash flows. At this time, we are not expecting the adoption of recently issued accounting standards to have a material impact to our financial condition, results of operations, and cash flows.

(4) Regulatory Matters

Montana Rate Review

In July 2024, we filed a Montana electric and natural gas rate review (2023 test year) with the Montana Public Service Commission (MPSC). The filing requests a base rate annual revenue increase of $156.5 million ($69.4 million net with Property Tax and Power Cost and Credit Recovery Mechanism (PCCAM) tracker adjustments) for electric and $28.6 million for natural gas. Our request is based on a return on equity of 10.80 percent with a capital structure including 46.81 percent equity, and forecasted 2024 electric and natural gas rate base of $3.45 billion and $731.9 million, respectively. The electric rate base investment includes the 175-megawatt natural gas-fired Yellowstone County Generating Station, which was placed in service in October 2024.

In November 2024, the MPSC partially approved our requested interim rates, which are subject to refund, increasing electric and natural gas base rates by $18.4 million and $17.4 million, respectively, and decreasing our PCCAM base costs by $88.0 million, effective December 1, 2024.

In January 2025, intervenor testimony was filed and we anticipate filing our rebuttal testimony in March 2025. Based on the procedural schedule developed by the MPSC, a hearing on our rate review request is scheduled to commence on April 22, 2025. If a final order is not received by May 23, 2025, which is 270 days from acceptance of our filing, we intend to implement, as permitted by the MPSC regulations, our requested rates, which will be subject to refund, until a final order is received.

(5) Regulatory Assets and Liabilities

We prepare our Consolidated Financial Statements in accordance with the provisions of ASC 980, as discussed in Note 3 - Significant Accounting Policies. Pursuant to this guidance, certain expenses and credits, normally reflected in income as incurred, are deferred and recognized when included in rates and recovered from or refunded to customers. Regulatory assets and liabilities are recorded based on management's assessment that it is probable that a cost will be recovered or that an obligation has been incurred. Accordingly, we have recorded the following major classifications of regulatory assets and liabilities that will be recognized in expenses and revenues in future periods when the matching revenues are collected or refunded. Of these regulatory assets and liabilities, energy supply costs are the only items earning a rate of return. The remaining regulatory items have corresponding assets and liabilities that will be paid for or refunded in future periods.

	Note Reference	Remaining Amortization Period	December 31,
			2024	2023
			(in thousands)
Flow-through income taxes	13	Plant Lives	$ 522,015	$ 483,949
Pension	15	See Note 15	56,719	73,823
Excess deferred income taxes	13	Plant Lives	39,040	44,657
Employee related benefits	15	See Note 15	17,877	21,926
Wildfire Mitigation		Undetermined	17,368	1,623
Deferred financing costs	12	See Note 12	16,961	18,540
State & local taxes & fees		1 Year	8,863	2,733
Supply costs		1 Year	1,132	3,895
Other		Various	15,098	22,811
Total Regulatory Assets			$ 695,073	$ 673,957
Removal cost	7	Plant Lives	$ 444,058	$ 435,470
Excess deferred income taxes	13	Plant Lives	108,154	117,870
State & local taxes & fees		1 Year	46	29,686
Supply costs		1 Year	5,093	924
Gas storage sales		16 years	6,205	6,625
Other		Various	1,977	905
Total Regulatory Liabilities			$ 565,533	$ 591,480

Income Taxes

Flow-through income taxes primarily reflect the effects of plant related temporary differences such as flow-through of depreciation, repairs related deductions, and removal costs that we will recover or refund in future rates. We amortize these amounts as temporary differences reverse. Excess deferred income tax assets and liabilities are recorded as a result of the Tax Cuts and Jobs Act and will be recovered or refunded in future rates. See Note 13 - Income Taxes for further discussion.

Pension and Employee Related Benefits

We recognize the unfunded portion of plan benefit obligations in the Consolidated Balance Sheets, which is remeasured at each year end, with a corresponding adjustment to regulatory assets/liabilities as the costs associated with these plans are recovered in rates. The MPSC allows recovery of pension costs on a cash funding basis. The portion of the regulatory asset related to our Montana pension plan will amortize as cash funding amounts exceed accrual expense under GAAP. The MPSC allows recovery of postretirement benefit costs on an accrual basis.

Deferred Financing Costs

Consistent with our historical regulatory treatment, a regulatory asset has been established to reflect the remaining deferred financing costs on long-term debt that has been replaced through the issuance of new debt. These amounts are amortized over the life of the new debt.

Enhanced Wildfire Mitigation Plan

We have developed an Enhanced Wildfire Mitigation Plan addressing five key areas: situational awareness, operational practices, system preparedness, vegetation management, and public communications outreach. Because of ever-increasing wildfire risk, our plan includes greater focus on situational awareness to monitor changing environmental conditions, operational practices that are more reactive to changing conditions, increased frequency of patrol and repairs, and more robust system hardening programs that target higher risk segments in our transmission and distribution systems. The MPSC has approved the deferral of incremental operating costs related to this Enhanced Wildfire Mitigation Plan.

Supply Costs

The MPSC has authorized the use of electric and natural gas supply cost trackers that enable us to track actual supply costs and either recover the under collection or refund the over collection to our customers. Accordingly, we have recorded a regulatory asset and liability to reflect the future recovery of under collections and refunding of over collections through the ratemaking process. We earn interest on natural gas supply costs under collected, or apply interest to an over collection, of 6.7 percent. For our electric supply tracker, the PCCAM, the interest rate we earn on supply costs under collected, or the interest rate we apply to an over collection, is based on the monthly interest rate for three month commercial paper as published by the Federal Reserve.

State & Local Taxes & Fees (Montana Property Tax Tracker)

Under Montana law, we are allowed to track the changes in the actual level of state and local taxes and fees and recover the increase, or refund the decrease, in rates, less the amount allocated to Federal Energy Regulatory Commission jurisdictional customers and net of the related income tax benefit.

Removal Cost

The anticipated costs of removing assets upon retirement are collected from customers in advance of removal activity as a component of depreciation expense. Our depreciation method, including cost of removal, is established by the respective regulatory commissions. Therefore, consistent with this regulated treatment, we reflect this accrual of removal costs for our regulated assets by increasing our regulatory liability. See Note 7 - Asset Retirement Obligations, for further information regarding this item.

Gas Storage Sales

A regulatory liability was established in 2000 and 2001 based on gains on cushion gas sales in Montana. This gain is being flowed to customers over a period that matches the depreciable life of surface facilities that were added to maintain deliverability from the field after the withdrawal of the gas. This regulatory liability is a reduction of rate base.

(6) Property, Plant and Equipment

The following table presents the major classifications of our property, plant and equipment (in thousands):

	December 31,
	2024	2023
	(in thousands)
Electric Plant	$ 4,888,326	$ 4,343,235
Natural Gas Plant	1,328,386	1,244,451
Plant acquisition adjustment(1)	656,319	656,319
Common and Other Plant	204,663	193,783
Construction work in process	133,740	352,377
Total property, plant and equipment	7,211,434	6,790,165
Less accumulated depreciation	(1,561,647)	(1,502,887)
Less accumulated amortization	(344,785)	(315,082)
Net property, plant and equipment	$ 5,305,002	$ 4,972,196

(1) The plant acquisition adjustment balance above includes our hydro generating assets acquired in 2014 and the inclusion of our interest in Colstrip Unit 4 in rate base in 2009. The acquisition adjustment is amortized on a straight-line basis over the estimated remaining useful life of each related asset in depreciation expense.

Net plant and equipment under finance lease were $3.0 million and $5.2 million as of December 31, 2024 and 2023, respectively, which is primarily comprised of a long-term power supply contract with the owners of a natural gas fired peaking plant, which has been accounted for as a finance lease.

Jointly Owned Electric Generating Plant

We have a 30% ownership interest in Colstrip Unit 4, a base-load electric generating plant, which is coal fired and operated by Talen Montana, LLC (Talen). Talen has a 30 percent ownership interest in Colstrip Unit 3. We have a reciprocating sharing agreement with Talen regarding the operation of Colstrip Units 3 and 4, in which each party receives 15 percent of the respective combined output and is responsible for 15 percent of the respective operating and construction costs, regardless of whether a particular cost is specified to Colstrip Unit 3 or 4. However, each party if responsible for its own fuel-related costs. Our interest in this plant is reflected in the Consolidated Balance Sheets on a pro rata basis and our share of operating expenses is reflected in the Consolidated Statements of Income. The participants each finance their own investment.

In January 2023 and July 2024, we entered into definitive agreements, the first with Avista and the second with Puget, to acquire their respective interests in Colstrip Units 3 & 4. In particular, we agreed to acquire a 15% (222 megawatts) interest from Avista and a 25% (370 megawatts) interest from Puget. Both agreements provide that the purchase price will be $0. These agreements are substantially similar and are both scheduled to close December 31, 2025, subject to the satisfaction of customary closing conditions and approvals contained within the agreements. Under the terms of the agreements, we will be responsible for operating costs starting on January 1, 2026; while Puget and Avista will remain responsible for their respective pre-closing share of environmental and pension liabilities attributed to events or conditions existing prior to the closing of the transaction and for any future decommission and demolition costs associated with the existing facilities that comprise their interests.

Acquisition of Avista and Puget's interests would result in our ownership of 55 percent of the facility with the ability to guide operating and maintenance investments. This would provide capacity to help us meet our obligation to provide reliable and cost effective power to our customers in Montana, while allowing opportunity for us to identify and plan for newer lower or no-carbon technologies in the future.

Either party may terminate the respective separate agreement if any requested regulatory approval is denied or if the closing has not occurred by December 31, 2025 or if any law or order would delay or impair closing.

Information relating to our ownership interest in this facility is as follows (in thousands):

	Colstrip Unit 4
December 31, 2024
Ownership percentages	30.0 %
Plant in service	$ 330,888
Accumulated depreciation	137,153
December 31, 2023
Ownership percentages	30.0 %
Plant in service	$ 323,793
Accumulated depreciation	127,381

(7) Asset Retirement Obligations

We are obligated to dispose of certain long-lived assets upon their abandonment. We recognize a liability for the legal obligation to perform an asset retirement activity in which the timing and/or method of settlement are conditional on a future event. We measure the liability at fair value when incurred and capitalize a corresponding amount as part of the book value of the related assets, which increases our property, plant and equipment and other noncurrent liabilities. The increase in the capitalized cost is included in determining depreciation expense over the estimated useful life of these assets. Since the fair value of the asset retirement obligation (ARO) is determined using a present value approach, accretion of the liability due to the passage of time is recognized each period and recorded as a regulatory asset until the settlement of the liability. Revisions to estimated AROs can result from changes in retirement cost estimates, revisions to estimated inflation rates, and changes in the estimated timing of abandonment. If the obligation is settled for an amount other than the carrying amount of the liability, we will recognize a regulatory asset or liability for the difference, which will be surcharged/refunded to customers through the rate making process. We record regulatory assets and liabilities for differences in timing of asset retirement costs recovered in rates and AROs recorded since asset retirement costs are recovered through rates charged to customers.

Our AROs relate to the reclamation and removal costs at our jointly-owned coal-fired generation facility, U.S. Department of Transportation requirements to cut, purge and cap retired natural gas pipeline segments, our obligation to plug and abandon oil and gas wells at the end of their life, and to remove all above-ground wind power facilities and restore the soil surface at the end of their life. The following table presents the change in our ARO (in thousands):

	December 31,
	2024	2023
Liability at January 1,	$ 34,808	$ 33,861
Accretion expense	1,626	1,575
Liabilities incurred	—	—
Liabilities settled	(1,923)	(1,151)
Revisions to cash flows	(299)	523
Liability at December 31,	$ 34,212	$ 34,808

During the twelve months ended December 31, 2024 our ARO liability decreased $1.9 million for partial settlement of the legal obligations at our jointly-owned coal-fired generation facility and natural gas pipeline segments. Additionally, during the twelve months ended December 31, 2024, our ARO liability decreased $0.3 million related to changes in both the timing and amount of retirement cost estimates.

In addition, we have identified removal liabilities related to our electric and natural gas transmission and distribution assets that have been installed on easements over property not owned by us. The easements are generally perpetual and only require remediation action upon abandonment or cessation of use of the property for the specified purpose. The ARO liability is not estimable for such easements as we intend to utilize these properties indefinitely. In the event we decide to abandon or cease the use of a particular easement, an ARO liability would be recorded at that time. We also identified AROs associated with our hydroelectric generating facilities; however, due to the indeterminate removal date, the fair value of the associated liabilities currently cannot be estimated and no amounts are recognized in the Consolidated Financial Statements.

We collect removal costs in rates for certain transmission and distribution assets that do not have associated AROs. Generally, the accrual of future non-ARO removal obligations is not required; however, long-standing ratemaking practices approved by applicable state and federal regulatory commissions have allowed provisions for such costs in historical depreciation rates. The recorded amounts of costs collected from customers through depreciation rates are classified as a regulatory liability in recognition of the fact that we have collected these amounts that will be used in the future to fund asset retirement costs and do not represent legal retirement obligations. See Note 5 - Regulatory Assets and Liabilities for removal costs recorded as regulatory liabilities on the Consolidated Balance Sheets as of December 31, 2024 and 2023.

(8) Goodwill

We completed our annual goodwill impairment test as of April 1, 2024, and no impairment was identified. We calculate the fair value of our reporting units by considering various factors, including valuation studies based primarily on a discounted cash flow analysis, with published industry valuations and market data as supporting information. Key assumptions in the determination of fair value include the use of an appropriate discount rate and estimated future cash flows. In estimating cash flows, we incorporate expected long-term growth rates in our service territory, regulatory stability, and commodity prices (where appropriate), as well as other factors that affect our revenue, expense and capital expenditure projections.

Goodwill by segment is as follows (in thousands):

	December 31,
	2024	2023
Electric	$ 179,890	$ 179,890
Natural gas	83,917	83,917
Total Goodwill	$ 263,807	$ 263,807

(9) Risk Management and Hedging Activities

Nature of Our Business and Associated Risks

We are exposed to certain risks related to the ongoing operations of our business, including the impact of market fluctuations in the price of electricity and natural gas commodities and changes in interest rates. We rely on market purchases to fulfill a portion of our electric and natural gas supply requirements. Several factors influence price levels and volatility. These factors include, but are not limited to, seasonal changes in demand, weather conditions, available generating assets within regions, transportation availability and reliability within and between regions, fuel availability, market liquidity, and the nature and extent of current and potential federal and state regulations.

Objectives and Strategies for Using Derivatives

To manage our exposure to fluctuations in commodity prices we routinely enter into derivative contracts. These types of contracts are included in our electric and natural gas supply portfolios and are used to manage price volatility risk by taking advantage of fluctuations in market prices. While individual contracts may be above or below market value, the overall portfolio approach is intended to provide greater price stability for consumers. We do not maintain a trading portfolio, and our derivative transactions are only used for risk management purposes consistent with regulatory guidelines.

In addition, we may use interest rate swaps to manage our interest rate exposures associated with new debt issuances or to manage our exposure to fluctuations in interest rates on variable rate debt.

Accounting for Derivative Instruments

We evaluate new and existing transactions and agreements to determine whether they are derivatives. The permitted accounting treatments include: NPNS; cash flow hedge; fair value hedge; and mark-to-market.

Mark-to-market accounting is the default accounting treatment for all derivatives unless they qualify, and we specifically designate them, for one of the other accounting treatments. Derivatives designated for any of the elective accounting treatments must meet specific, restrictive criteria both at the time of designation and on an ongoing basis. The changes in the fair value of recognized derivatives are recorded each period in current earnings or other comprehensive income, depending on whether a derivative is designated as part of a hedge transaction and the type of hedge transaction.

Normal Purchases and Normal Sales

We have applied the NPNS scope exception to our contracts involving the physical purchase and sale of gas and electricity at fixed prices in future periods. During our normal course of business, we enter into full-requirement energy contracts, power purchase agreements and physical capacity contracts, which qualify for NPNS. All of these contracts are accounted for using the accrual method of accounting; therefore, there were no unrealized amounts recorded in the Consolidated Financial Statements at December 31, 2024 and 2023. Revenues and expenses from these contracts are reported on a gross basis in the appropriate revenue and expense categories as the commodities are received or delivered.

Credit Risk

Credit risk is the potential loss resulting from counterparty non-performance under an agreement. We manage credit risk with policies and procedures for, among other things, counterparty analysis and exposure measurement, monitoring and mitigation. We limit credit risk in our commodity and interest rate derivatives activities by assessing the creditworthiness of potential counterparties before entering into transactions with them and continuing to evaluate their creditworthiness on an ongoing basis.

We are exposed to credit risk through buying and selling electricity and natural gas to serve customers. We may request collateral or other security from our counterparties based on the assessment of creditworthiness and expected credit exposure. It is possible that volatility in commodity prices could cause us to have material credit risk exposures with one or more counterparties. We enter into commodity master enabling agreements with our counterparties to mitigate credit exposure, as these agreements reduce the risk of default by allowing us or our counterparty the ability to make net payments. The agreements generally are: (1) Western Systems Power Pool agreements – standardized power purchase and sales contracts in the electric industry; (2) International Swaps and Derivatives Association agreements – standardized financial gas and electric contracts; (3) North American Energy Standards Board agreements – standardized physical gas contracts; and (4) Edison Electric Institute Master Purchase and Sale Agreements – standardized power sales contracts in the electric industry.

Many of our forward purchase contracts contain provisions that require us to maintain an investment grade credit rating from each of the major credit rating agencies. If our credit rating were to fall below investment grade, the counterparties could require immediate payment or demand immediate and ongoing full overnight collateralization on contracts in net liability positions.

Interest Rate Swaps Designated as Cash Flow Hedges

We have previously used interest rate swaps designated as cash flow hedges to manage our interest rate exposures associated with new debt issuances. We have no interest rate swaps outstanding. These swaps were designated as cash flow hedges with the effective portion of gains and losses, net of associated deferred income tax effects, recorded in AOCL. We reclassify these gains from AOCL into interest expense during the periods in which the hedged interest payments occur. The following table shows the effect of these interest rate swaps previously terminated on the Consolidated Financial Statements (in thousands):

Cash Flow Hedges		Location of Amount Reclassified from AOCL to Income		Amount Reclassified from AOCL into Income during the Year Ended December 31, 2024
Interest rate contracts		Interest Expense		$ 612

A pre-tax loss of approximately $12.1 million is remaining in AOCL as of December 31, 2024, and we expect to reclassify approximately $0.6 million of pre-tax losses from AOCL into interest expense during the next twelve months. These amounts relate to terminated swaps.

(10) Fair Value Measurements

Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (i.e., an exit price). Measuring fair value requires the use of market data or assumptions that market participants would use in pricing the asset or liability, including assumptions about risk and the risks inherent in the inputs to the valuation technique. These inputs can be readily observable, corroborated by market data, or generally unobservable. Valuation techniques are required to maximize the use of observable inputs and minimize the use of unobservable inputs.

Applicable accounting guidance establishes a hierarchy that prioritizes the inputs used to measure fair value, and requires fair value measurements to be categorized based on the observability of those inputs. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 inputs) and the lowest priority to unobservable inputs (Level 3 inputs). The three levels of the fair value hierarchy are as follows:

• Level 1 – Unadjusted quoted prices available in active markets at the measurement date for identical assets or liabilities;

• Level 2 – Pricing inputs, other than quoted prices included within Level 1, which are either directly or indirectly observable as of the reporting date; and

• Level 3 – Significant inputs that are generally not observable from market activity.

We classify assets and liabilities within the fair value hierarchy based on the lowest level of input that is significant to the fair value measurement of each individual asset and liability taken as a whole. Due to the short-term nature of cash and cash equivalents, accounts receivable, net, accounts payable, and short-term borrowings, the carrying amount of each such item approximates fair value. The table below sets forth by level within the fair value hierarchy the gross components of our assets and liabilities measured at fair value on a recurring basis. NPNS transactions are not included in the fair values by source table as they are not recorded at fair value. See Note 9 - Risk Management and Hedging Activities for further discussion.

We record transfers between levels of the fair value hierarchy, if necessary, at the end of the reporting period. There were no transfers between levels for the periods presented.

December 31, 2024	Quoted Prices in Active Markets for Identical Assets or Liabilities (Level 1)	Significant Other Observable Inputs (Level 2)	Significant Unobservable Inputs (Level 3)	Margin Cash Collateral Offset	Total Net Fair Value
	(in thousands)
Rabbi trust investments	14,136	—	—	—	14,136
Total	$ 14,136	$ —	$ —	$ —	$ 14,136

December 31, 2023
Restricted cash equivalents	$ 14,857	$ —	$ —	$ —	$ 14,857
Rabbi trust investments	13,030	—	—	—	13,030
Total	$ 27,887	$ —	$ —	$ —	$ 27,887

Rabbi trust investments represent assets held for non-qualified deferred compensation plans, which consist of our common stock and actively traded mutual funds with quoted prices in active markets.

Financial Instruments

The estimated fair value of financial instruments is summarized as follows (in thousands):

	December 31, 2024		December 31, 2023
	Carrying Amount	Fair Value	Carrying Amount	Fair Value
Liabilities:
Long-term debt	$ 2,406,206	$ 2,104,381	$ 2,223,561	$ 2,000,767

The estimated fair value amounts have been determined using available market information and appropriate valuation methodologies; however, considerable judgment is required in interpreting market data to develop estimates of fair value. Accordingly, the estimates presented herein are not necessarily indicative of the amounts that we would realize in a current market exchange.

We determined fair value for long-term debt based on interest rates that are currently available to us for issuance of debt with similar terms and remaining maturities, except for publicly traded debt, for which fair value is based on market prices for the same or similar issues or upon the quoted market prices of U.S. treasury issues having a similar term to maturity, adjusted for our bond issuance rating and the present value of future cash flows. These are significant other observable inputs, or level 2 inputs, in the fair value hierarchy.

(11) Unsecured Credit Facilities

On November 29, 2023 we amended our existing $425.0 million revolving credit facility (the Amended Facility) to address the holding company reorganization and extended the maturity date of the facility to November 29, 2028. The Amended Facility does not amortize and is unsecured. Borrowings may be made at interest rates equal to (a) SOFR, plus a credit spread adjustment of 10.0 basis points plus a margin of 100.0 to 175.0 basis points, or (b) a base rate, plus a margin of 0.0 to 75.0 basis points. After the completion of the holding company reorganization on January 1, 2024, we own and operate only the Montana regulated utility, and the base capacity of the Amended Facility automatically reduced to $400.0 million. The Amended Facility has uncommitted features that allow us to request one-year extensions to the maturity date and increase the size of the Amended Facility by an additional $100.0 million.

On January 24, 2025, we amended our existing $400.0 million Amended Facility to increase the capacity to $425.0 million. This amendment did not affect the maturity date or borrowing rates.

On January 2, 2024, we terminated our $100.0 million Additional Credit Facility. On January 4, 2024, we terminated our $25.0 Swingline Facility.

Commitment fees for the unsecured revolving lines of credit were $0.4 million and $0.5 million for the years ended December 31, 2024 and 2023.

The availability under the facilities in place for the years ended December 31 is shown in the following table (in millions):

	2024	2023
Unsecured revolving line of credit, expiring November 2028	400.0	425.0
Unsecured revolving line of credit, expiring April 2024	—	100.0
Unsecured revolving line of credit, expiring March 2025	—	25.0
	400.0	550.0

Amounts outstanding at December 31:
SOFR borrowings	342.0	264.0
Letters of credit	—	—
	342.0	264.0

Net availability as of December 31(1)	$ 58.0	$ 286.0

(1) As discussed above, upon the completion of the holding company reorganization and termination of the Additional Credit Facility and Swingline facility in January 2024, our total consolidated capacity decreased to $400.0 million.

Our credit facilities include covenants that require us to meet certain financial tests, including a maximum debt to capitalization ratio not to exceed 65 percent. The facilities also contain covenants which, among other things, limit our ability to engage in any consolidation or merger or otherwise liquidate or dissolve, dispose of property, and enter into transactions with affiliates. A default on the Montana First Mortgage Bonds would trigger a cross default on the Amended Facility; however, a default on the Amended Facility would not trigger a default on the Montana First Mortgage Bonds.

(12) Long-Term Debt and Finance Leases

Long-term debt and finance leases consisted of the following (in thousands):

		December 31,
	Due	2024	2023
Unsecured Debt:
Unsecured Revolving Line of Credit	2028	$ 342,000	$ 264,000
Secured Debt:
Mortgage bonds—
Montana—1.00%	2024	—	100,000
Montana—5.01%	2025	161,000	161,000
Montana—3.11%	2025	75,000	75,000
Montana—3.99%	2028	35,000	35,000
Montana—3.21%	2030	100,000	100,000
Montana—5.57%	2031	175,000	—
Montana—5.57%	2033	239,000	239,000
Montana—5.71%	2039	55,000	55,000
Montana—4.15%	2042	60,000	60,000
Montana—4.85%	2043	15,000	15,000
Montana—4.176%	2044	450,000	450,000
Montana—4.11%	2045	125,000	125,000
Montana—4.03%	2047	250,000	250,000
Montana—3.98%	2049	150,000	150,000
Montana—4.30%	2052	40,000	40,000
Pollution control obligations—
Montana—3.88%	2028	144,660	144,660
Other Long Term Debt:
Discount on Notes and Bonds and Debt Issuance Costs, Net	—	(10,454)	(11,099)
Total Long-Term Debt		$ 2,406,206	$ 2,252,561
Less current maturities (including associated debt issuance costs)		(235,959)	(99,950)
Total Long-Term Debt, Net of Current Maturities		$ 2,170,247	$ 2,152,611

Finance Leases:
Total Finance Leases	2026	$ 5,461	$ 8,799
Less current maturities		(3,596)	(3,338)
Total Long-Term Finance Leases		$ 1,865	$ 5,461

Secured Debt

First Mortgage Bonds and Pollution Control Obligations

The Montana First Mortgage Bonds are a series of general obligation bonds issued under our Montana indenture. These bonds are secured by our electric and natural gas assets associated with its utility operations.

On March 30, 2023, we issued and sold $239.0 million aggregate principal amount of Montana First Mortgage Bonds (the bonds) at a fixed interest rate of 5.57 percent maturing on March 30, 2033. These bonds were issued in transactions exempt from the registration requirements of the Securities Act of 1933. Proceeds were used to repay a portion of our outstanding borrowings under our revolving credit facilities and for other general corporate purposes.

On June 29, 2023, the City of Forsyth, Rosebud County, Montana issued $144.7 million principal amount of Pollution Control Revenue Refunding Bonds (2023 Pollution Control Bonds) on our behalf. The 2023 Pollution Control Bonds were issued at a fixed interest rate of 3.88 percent maturing on July 1, 2028. The proceeds of the issuance were loaned to us pursuant to a Loan Agreement and were deposited directly with U.S. Bank Trust Company, National Association, as trustee, for the redemption of the 2.00 percent, $144.7 million City of Forsyth Pollution Control Revenue Refunding Bonds due on August 1, 2023 that had previously been issued on our behalf. Pursuant to the Loan Agreement, we are obligated to make payments in such amounts and at such times as will be sufficient to pay, when due, the principal and interest on the 2023 Pollution Control Bonds. Our obligations under the Loan Agreement are secured by delivery of a like amount of our Montana First Mortgage Bonds, which are secured by our Montana electric and natural gas assets. So long as we are making payments under the Loan Agreement, no payments under these mortgage bonds will be due. The 2023 Pollution Control Bonds were issued in a transaction exempt from the registration requirements of the Securities Act of 1933, as amended.

On March 28, 2024, we issued and sold $175.0 million aggregate principal amount of Montana First Mortgage Bonds at a fixed interest rate of 5.56 percent maturing on March 28, 2031. These bonds were issued in transactions exempt from the registration requirements of the Securities Act of 1933. Proceeds were used to redeem the $100.0 million of Montana First Mortgage Bonds due this year and for other general utility purposes. The bonds are secured by our electric and natural gas assets associated with its Montana utility operations.

As of December 31, 2024, we were in compliance with our financial debt covenants.

Maturities of Long-Term Debt

The aggregate minimum principal maturities of long-term debt and finance leases, during the next five years are $239.6 million in 2025, $1.9 million in 2026, and $521.7 million in 2028.

(13) Income Taxes

Income tax expense (benefit) is comprised of the following (in thousands):

	Year Ended December 31,
	2024	2023
Federal
Current	$ 1,667	$ (3,874)
Deferred	13,602	16,140
Investment tax credits	1,970	(129)
State
Current	61	(1,590)
Deferred	2,365	3,847
Income Tax Expense	$ 19,665	$ 14,394

Our effective tax rate typically differs from the federal statutory tax rate primarily due to production tax credits and the regulatory impact of flowing through the federal and state tax benefit of repairs deductions, state tax benefit of accelerated tax depreciation deductions (including bonus depreciation when applicable), and production tax credits. The regulatory accounting treatment of these deductions requires immediate income recognition for temporary tax differences of this type, which is referred to as the flow-through method. When the flow-through method of accounting for temporary differences is reflected in regulated revenues, we record deferred income taxes and establish related regulatory assets and liabilities.

The following table reconciles our effective income tax rate to the federal statutory rate:

	Year Ended December 31,
	2024	2023
Federal statutory rate	21.0 %	21.0 %
State income tax, net of federal provisions	0.9	0.9
Flow-through repairs deductions	(9.6)	(11.5)
Gas repairs safe harbor method change	(2.2)	—
Amortization of excess deferred income taxes	(1.2)	(0.8)
Production tax credits	(1.1)	(1.4)
Prior year permanent return to accrual adjustments	(0.3)	—
Plant and depreciation of flow through items	3.3	2.8
Release of unrecognized tax benefits	—	(1.4)
Other, net	(1.0)	(1.8)
Effective tax rate	9.8 %	7.8 %

The table below summarizes the significant differences in income tax expense (benefit) based on the differences between our effective tax rate and the federal statutory rate (in thousands). All of our income from continuing operations is primarily from domestic operations.

	Year Ended December 31,
	2024	2023
Income Before Income Taxes	$ 199,744	$ 185,168

Income tax calculated at federal statutory rate	41,946	38,885

Permanent or flow through adjustments:
State income, net of federal provisions	1,719	1,641
Flow-through repairs deductions	(19,274)	(21,379)
Gas repairs safe harbor method change	(4,366)	—
Amortization of excess deferred income taxes	(2,465)	(1,479)
Production tax credits	(2,288)	(2,582)
Prior year permanent return to accrual adjustments	(567)	47
Plant and depreciation of flow through items	6,690	5,167
Release of unrecognized tax benefits	—	(2,680)
Other, net	(1,730)	(3,226)
	(22,281)	(24,491)

Income Tax Expense	$ 19,665	$ 14,394

We and our subsidiaries are included in NorthWestern Energy Group, Inc.'s consolidated federal and state income tax returns. In accordance with our tax sharing agreement with NorthWestern Energy Group, Inc., we compute our income taxes based upon the separate return method, where we are assumed to file a separate return with the taxing authority, thereby reporting our taxable income and paying the applicable tax to or receiving the appropriate refund from NorthWestern Energy Group, Inc.

In 2023, the Internal Revenue Service (IRS) issued a safe harbor method of accounting for the repair and maintenance of natural gas transmission and distribution property. For the year ending December 31, 2024, after completion of our impact analysis of the gas repairs safe harbor method change, we recorded an income tax benefit of approximately $4.4 million related to tax deductions for repair costs that were previously capitalized in the 2022 and prior tax years.

The components of the net deferred income tax liability recognized in our Consolidated Balance Sheets are related to the following temporary differences (in thousands):

	December 31,
	2024	2023
NOL carryforward	$ 89,816	82,351
Production tax credit	35,602	$ 33,279
Customer advances	32,455	28,300
Pension / postretirement benefits	10,369	16,352
Compensation accruals	9,857	8,319
Interest rate hedges	3,205	3,367
Unbilled revenue	3,126	7,222
Reserves and accruals	2,133	2,952
Environmental liability	2,131	2,222
Other, net	4,334	3,407
Deferred Tax Asset	193,028	187,771
Excess tax depreciation	(599,893)	(552,815)
Flow through depreciation	(119,674)	(108,413)
Goodwill amortization	(89,687)	(88,183)
Regulatory assets and other	(23,721)	(18,572)
Deferred Tax Liability	(832,975)	(767,983)
Deferred Tax Liability, net	$ (639,947)	$ (580,212)

As of December 31, 2024, our total federal net operation loss (NOL) carryforward was approximately $342.6 million. Our federal NOL carryforward does not expire. Our state NOL carryforward as of December 31, 2024 was approximately $335.3 million. If unused, our state NOL carryforwards will expire in 2033. We believe it is more likely than not that sufficient taxable income will be generated to utilize these NOL carryforwards.

At December 31, 2024, our total production tax credit carryforward was approximately $35.6 million. If unused, our production tax credit carryforwards will expire as follows: $1.2 million in 2035, $3.4 million in 2036, $3.5 million in 2037, $3.9 million in 2038, $4.4 million in 2039, $5.4 million in 2040, $4.4 million in 2041, $4.5 million in 2042, $2.6 million in 2043, and $2.3 million in 2044 . We believe it is more likely than not that sufficient taxable income will be generated to utilize these production tax credit carryforwards.

Uncertain Tax Positions

We recognize tax positions that meet the more-likely-than-not threshold as the largest amount of tax benefit that is greater than 50 percent likely of being realized upon ultimate settlement with a taxing authority that has full knowledge of all relevant information. The change in unrecognized tax benefits is as follows (in thousands):

	2024	2023
Unrecognized Tax Benefits at January 1	$ 5,179	$ 7,310
Gross increases - tax positions in prior period	—	—
Gross increases - tax positions in current period	—	—
Gross decreases - tax positions in current period	(1,569)	(2,131)
Lapse of statute of limitations	—	—
Unrecognized Tax Benefits at December 31	$ 3,610	$ 5,179

Our unrecognized tax benefits include approximately $1.4 million related to tax positions as of December 31, 2024 and 2023, that if recognized, would impact our annual effective tax rate. On April 14, 2023, the Internal Revenue Service (IRS) issued Revenue Procedure 2023-15, which provides a safe harbor method of accounting for gas repairs expenditures. During the year ended December 31, 2023, we adopted this method and decreased our total unrecognized tax benefits by $0.4 million and recognized an income tax benefit of approximately $2.7 million for previously unrecognized tax benefits. We do not anticipate that total unrecognized tax benefits will significantly change due to the settlement of audits or the expiration of statutes of limitation within the next twelve months.

Our policy is to recognize interest and penalties related to uncertain tax positions in income tax expense. As of December 31, 2024, we have accrued $1.7 million for the payment of interest and penalties in the Consolidated Balance Sheets. As of December 31, 2023, we had $1.0 million accrued for the payment of interest and penalties.

Tax years 2021 and forward remain subject to examination by the IRS and state taxing authorities. During the first quarter of 2023 the IRS commenced and concluded a limited scope examination of our 2019 amended federal income tax return.

(14) Comprehensive Income (Loss)

The following tables display the components of Other Comprehensive Income (Loss), after-tax, and the related tax effects (in thousands):

	December 31,
	2024			2023
	Before-Tax Amount	Tax Expense (Benefit)	Net-of-Tax Amount	Before-Tax Amount	Tax Expense	Net-of-Tax Amount
Foreign currency translation adjustment	$ (4)	$ —	$ (4)	$ 2	$ —	$ 2
Reclassification of net income (loss) on derivative instruments	612	(160)	452	612	(160)	452
Postretirement medical liability adjustment	—	—	—	(331)	69	(262)
Other comprehensive income (loss)	$ 608	$ (160)	$ 448	$ 283	$ (91)	$ 192

Balances by classification included within AOCL on the Consolidated Balance Sheets are as follows, net of tax (in thousands):

	December 31,
	2024	2023
Foreign currency translation	$ 1,433	$ 1,437
Derivative instruments designated as cash flow hedges	(8,921)	(9,373)
Postretirement medical plans	(45)	280
Accumulated other comprehensive loss	$ (7,533)	$ (7,656)

The following table displays the changes in AOCL by component, net of tax (in thousands):

		December 31, 2024
		Year Ended
	Affected Line Item in the Consolidated Statements of Income	Interest Rate Derivative Instruments Designated as Cash Flow Hedges	Postretirement Medical Plans	Foreign Currency Translation	Total
Beginning balance		$ (9,373)	$ 280	$ 1,437	$ (7,656)
Other comprehensive income before reclassifications		—	—	(4)	(4)
Amounts reclassified from AOCL	Interest Expense	452	—	—	452
Net current-period other comprehensive income (loss)		452	—	(4)	448
Distribution to Parent		$ —	$ (325)	$ —	$ (325)
Ending Balance		$ (8,921)	$ (45)	$ 1,433	$ (7,533)

		December 31, 2023
		Year Ended
	Affected Line Item in the Consolidated Statements of Income	Interest Rate Derivative Instruments Designated as Cash Flow Hedges	Postretirement Medical Plans	Foreign Currency Translation	Total
Beginning balance		$ (9,825)	$ 542	$ 1,435	$ (7,848)
Other comprehensive loss before reclassifications		—	—	2	2
Amounts reclassified from AOCL	Interest Expense	452	—	—	452
Amounts reclassified from AOCL		—	(262)	—	(262)
Net current-period other comprehensive income (loss)		452	(262)	2	192
Ending Balance		$ (9,373)	$ 280	$ 1,437	$ (7,656)

(15) Employee Benefit Plans

Pension and Other Postretirement Benefit Plans

We sponsor and/or contribute to pension, postretirement health care and life insurance benefit plans for eligible employees. The pension plan for our Montana employees is referred to as the NorthWestern Energy MT Plan (formerly known as the NorthWestern Energy Plan). We utilize a number of accounting mechanisms that reduce the volatility of reported pension costs. Differences between actuarial assumptions and actual plan results are deferred and are recognized into earnings only when the accumulated differences exceed 10 percent of the greater of the projected benefit obligation or the market-related value of plan assets. If necessary, the excess is amortized over the average remaining service period of active employees. The Plans' funded status is recognized as a liability in our Consolidated Financial Statements. See Note 5 - Regulatory Assets and Liabilities, for further discussion on how these costs are recovered through rates charged to our customers.

Benefit Obligation and Funded Status

Following is a reconciliation of the changes in plan benefit obligations and fair value of plan assets, and a statement of the funded status (in thousands):

	Pension Benefits		Other Postretirement Benefits
	December 31,		December 31,
	2024	2023	2024	2023
Change in benefit obligation:
Obligation at beginning of period	$ 427,326	$ 474,947	$ 10,598	$ 12,070
Service cost	5,099	5,105	252	272
Interest cost	20,725	23,535	456	554
Actuarial (gain) loss	(26,780)	2,235	(1,804)	(820)
Settlements(1)	(848)	(51,942)	—	—
Benefits paid	(20,719)	(26,554)	(1,163)	(1,478)
Benefit Obligation at End of Period	$ 404,803	$ 427,326	$ 8,339	$ 10,598
Change in Fair Value of Plan Assets:
Fair value of plan assets at beginning of period	$ 348,134	$ 388,693	$ 22,309	$ 20,055
Return on plan assets	8,026	29,937	3,177	3,334
Employer contributions	8,122	8,000	449	398
Settlements(1)	(848)	(51,942)	—	—
Benefits paid	(20,719)	(26,554)	(1,163)	(1,478)
Fair value of plan assets at end of period	$ 342,715	$ 348,134	$ 24,772	$ 22,309
Funded Status	$ (62,088)	$ (79,192)	$ 16,433	$ 11,711

Amounts Recognized in the Balance Sheet Consist of:
Noncurrent asset	—	—	16,943	12,378
Total Assets	—	—	16,943	12,378
Current liability	(10,000)	(10,000)	(510)	(667)
Noncurrent liability	(52,088)	(69,192)	—	—
Total Liabilities	(62,088)	(79,192)	(510)	(667)
Net amount recognized	$ (62,088)	$ (79,192)	$ 16,433	$ 11,711

Amounts Recognized in Regulatory Assets Consist of:
Prior service credit	—	—	—	—
Net actuarial (loss) gain	(30,843)	(43,097)	3,716	15
Total	$ (30,843)	$ (43,097)	$ 3,716	$ 15

(1) In October 2023, we entered into a group annuity contract from an insurance company to provide for the payment of pension benefits to select NorthWestern Energy MT Pension Plan participants. We purchased the contract with $51.9 million of plan assets in 2023. A trailing premium of $0.8 million related to final data reconciliation was paid from plan assets in 2024, reflecting a final annuitized participant count of 276. The insurance company took over the payments of these benefits starting January 1, 2024. This transaction settled $51.9 million of our NorthWestern Energy MT Pension Plan obligation. As a result of this transaction, during the twelve months ended December 31, 2023, we recorded a non-cash, non-operating settlement charge of $4.4 million. This charge is recorded within other income, net on the Consolidated Statements of Income. As discussed within Note 5 – Regulatory Assets and Liabilities, the MPSC allows recovery of pension costs on a cash funding basis. As such, this charge was deferred as a regulatory asset on the Consolidated Balance Sheets, with a corresponding decrease to operating and maintenance expense on the Consolidated Statements of Income.

The actuarial gain/loss is primarily due to the change in discount rate assumption and actual asset returns compared with expected amounts.

Net Periodic Cost (Credit)

The components of the net costs (credits) for our pension and other postretirement plans are as follows (in thousands):

	Pension Benefits		Other Postretirement Benefits
	December 31,		December 31,
	2024	2023	2024	2023
Components of Net Periodic Benefit Cost
Service cost	$ 5,099	$ 5,105	$ 252	$ 272
Interest cost	20,725	23,535	456	554
Expected return on plan assets	(22,585)	(23,448)	(1,280)	(1,096)
Amortization of prior service cost (credit)	—	—	—	116
Recognized actuarial loss (gain)	33	228	—	79
Settlement loss recognized(1)	—	4,395	—	—
Net Periodic Benefit Cost (Credit)	$ 3,272	$ 9,815	$ (572)	$ (75)

Regulatory deferral of net periodic benefit cost(2)	4,850	(1,814)	—	—
Previously deferred costs recognized(2)	—	—	181	550
Net Periodic Benefit Cost Recognized	$ 8,122	$ 8,001	$ (391)	$ 475

(1) Settlement losses are related to partial annuitization of the NorthWestern Energy MT Pension Plan effective October 24, 2023.

(2) Net periodic benefit costs for pension and postretirement benefit plans are recognized for financial reporting based on the authorization of each regulatory jurisdiction in which we operate. A portion of these costs are recorded in regulatory assets and recognized in the Consolidated Statements of Income as those costs are recovered through customer rates.

For the years ended December 31, 2024 and 2023 Service costs were recorded in Operating, general, and administrative expense while non-service costs were recorded in Other income, net on the Consolidated Statements of Income.

For purposes of calculating the expected return on pension plan assets, the market-related value of assets is used, which is based upon fair value. The difference between actual plan asset returns and estimated plan asset returns are amortized equally over a period not to exceed five years.

Actuarial Assumptions

The measurement dates used to determine pension and other postretirement benefit measurements for the plans are December 31, 2024 and 2023. The actuarial assumptions used to compute net periodic pension cost and postretirement benefit cost are based upon information available as of the beginning of the year, specifically, market interest rates, past experience and management's best estimate of future economic conditions. Changes in these assumptions may impact future benefit costs and obligations. In computing future costs and obligations, we must make assumptions about such things as employee mortality and turnover, expected salary and wage increases, discount rate, expected return on plan assets, and expected future cost increases. Two of these assumptions have the most impact on the level of cost: (1) discount rate and (2) expected rate of return on plan assets. During 2022, the plan's actuary conducted an experience study to review five years of plan experience and update these assumptions.

On an annual basis, we set the discount rate using a yield curve analysis. This analysis includes constructing a hypothetical bond portfolio whose cash flow from coupons and maturities matches the year-by-year, projected benefit cash flow from our plans. The increase in the discount rate during 2024 decreased our projected benefit obligation by approximately $27.6 million.

In determining the expected long-term rate of return on plan assets, we review historical returns, the future expectations for returns for each asset class weighted by the target asset allocation of the pension and postretirement portfolios, and long-term inflation assumptions. Based on the target asset allocation for our pension assets and future expectations for asset returns, we decreased our long term rate of return on assets assumption for NorthWestern Energy MT Pension Plan to 6.17 percent for 2025.

The weighted-average assumptions used in calculating the preceding information are as follows:

	Pension Benefits		Other Postretirement Benefits
	December 31,		December 31,
	2024	2023	2024	2023
Discount rate	5.60	5.00	5.45	4.90
Expected rate of return on assets	6.65	6.44	5.84	5.62
Long-term rate of increase in compensation levels (non-union)	4.00	4.00	4.00	4.00
Long-term rate of increase in compensation levels (union)	4.00	4.00	4.00	4.00
Interest crediting rate	6.00	6.00	N/A	N/A

The postretirement benefit obligation is calculated assuming that health care costs increase by a 5.00 percent fixed rate. The company contribution toward the premium cost is capped, therefore future health care cost trend rates are expected to have a minimal impact on company costs and the accumulated postretirement benefit obligation.

Investment Strategy

Our investment goals with respect to managing the pension and other postretirement assets are to meet current and future benefit payment needs while maximizing total investment returns (income and appreciation) after inflation within the constraints of diversification, prudent risk taking, Prudent Man Rule of the Employee Retirement Income Security Act of 1974 and liability-based considerations. Each plan is diversified across asset classes to achieve optimal balance between risk and return and between income and growth through capital appreciation. Our investment philosophy is based on the following:

• Each plan should be substantially invested as long-term cash holdings reduce long-term rates of return;

• Pension Plan portfolio risk is described by volatility in the funded status of the Plans;

• It is prudent to diversify each plan across the major asset classes;

• Equity investments provide greater long-term returns than fixed income investments, although with greater short-term volatility;

• Fixed income investments of the plans should strongly correlate with the interest rate sensitivity of the plan’s aggregate liabilities in order to hedge the risk of change in interest rates negatively impacting the pension plans overall funded status, (such assets will be described as Liability Hedging Fixed Income assets);

• Allocation to foreign equities increases the portfolio diversification and thereby decreases portfolio risk while providing for the potential for enhanced long-term returns;

• Private real estate and broad global opportunistic fixed income asset classes can provide diversification to both equity and liability hedging fixed income investments and that a moderate allocation to each can potentially improve the expected risk-adjusted return for the NorthWestern Energy Pension Plan investments over full market cycles;

• Active management can reduce portfolio risk and potentially add value through security selection strategies;

• A portion of plan assets should be allocated to passive, indexed management funds to provide for greater diversification and lower cost; and

• It is appropriate to retain more than one investment manager, provided that such managers offer asset class or style diversification.

Investment risk is measured and monitored on an ongoing basis through quarterly investment portfolio reviews, annual liability measurements, and periodic asset/liability studies.

The most important component of an investment strategy is the portfolio asset mix, or the allocation between the various classes of securities available. The mix of assets is based on an optimization study that identifies asset allocation targets in order to achieve the maximum return for an acceptable level of risk, while minimizing the expected contributions and pension and postretirement expense. In the optimization study, assumptions are formulated about characteristics, such as expected asset class investment returns, volatility (risk), and correlation coefficients among the various asset classes, and making adjustments to reflect future conditions expected to prevail over the study period. Based on this, the target asset allocation established, within an allowable range of plus or minus 5 percent, is as follows:

	NorthWestern Energy MT Pension		NorthWestern Energy Health and Welfare
	December 31,		December 31,
	2024	2023	2024	2023
Fixed income securities	45.0 %	45.0 %	40.0 %	40.0 %
Non-U.S. fixed income securities	—	—	—	—
Opportunistic fixed income	11.0	11.0	—	—
Global equities	38.5	38.5	60.0	60.0
Private real estate	5.5	5.5	—	—

The actual allocation by plan is as follows:

	NorthWestern Energy MT Pension		NorthWestern Energy Health and Welfare
	December 31,		December 31,
	2024	2023	2024	2023
Cash and cash equivalents	— %	— %	0.3 %	0.2 %
Fixed income securities(1)	43.7	45.3	32.2	35.1
Non-U.S. fixed income securities	—	—	—	—
Opportunistic fixed income	11.1	10.6	—	—
Global equities(1)	39.0	37.6	67.5	64.7
Private real estate	6.2	6.5	—	—
	100.0 %	100.0 %	100.0 %	100.0 %

(1) While the NorthWestern Energy Health and Welfare plan allocation of assets as of December 31, 2024, between Fixed income securities and Global equities is greater than 5 percent different from the target allocation, the plan Investment Manager has 60 days to correct this deviation from the plan.

Generally, the asset mix will be rebalanced to the target mix as individual portfolios approach their minimum or maximum levels. The guidelines allow for a transition to targets over time as assets are reallocated to newly-approved asset classes of opportunistic fixed income and private real estate. Debt securities consist of U.S. and international instruments including emerging markets and high yield instruments, as well as government, corporate, asset backed and mortgage backed securities. While the portfolio may invest in high yield securities, the average quality must be rated at least “investment grade" by rating agencies. Equity, real estate and fixed income portfolios may be comprised of both active and passive management strategies. Performance of fixed income investments is measured by both traditional investment benchmarks as well as relative changes in the present value of the plan's liabilities. Equity investments consist primarily of U.S. stocks including large, mid and small cap stocks. We also invest in global equities with exposure to developing and emerging markets. Equity investments may also be diversified across investment styles such as growth and value. Derivatives, options and futures are permitted for the purpose of reducing risk but may not be used for speculative purposes. Real estate investments will consist of global equity or debt interests in tangible property consisting of land, buildings, and other improvements in commercial and residential sectors.

Our plan assets are primarily invested in common collective trusts (CCTs), which are invested in equity and fixed income securities. In accordance with our investment policy, these pooled investment funds must have an adequate asset base relative to their asset class and be invested in a diversified manner and have a minimum of three years of verified investment performance experience or verified portfolio manager investment experience in a particular investment strategy and have management and oversight by an investment advisor registered with the SEC. Investments in a collective investment vehicle are valued by multiplying the investee company’s net asset value per share with the number of units or shares owned at the valuation date. Net asset value per share is determined by the trustee. Investments held by the CCT, including collateral invested for securities on loan, are valued on the basis of valuations furnished by a pricing service approved by the CCT’s investment manager, which determines valuations using methods based on quoted closing market prices on national securities exchanges, or at fair value as determined in good faith by the CCT’s investment manager if applicable. The funds do not contain any redemption restrictions. The direct holding of NorthWestern Corporation or any affiliate's stock is not permitted; however, any holding in a diversified mutual fund or collective investment fund is permitted.

Cash Flows

In accordance with the Pension Protection Act of 2006 (PPA), and the relief provisions of the Worker, Retiree, and Employer Recovery Act of 2008 (WRERA), we are required to meet minimum funding levels in order to avoid required contributions and benefit restrictions. We have elected to use asset smoothing provided by the WRERA, which allows the use of asset averaging, including expected returns (subject to certain limitations), for a 24-month period in the determination of funding requirements. Additional funding relief was passed in the American Rescue Plan Act of 2021, providing for longer amortization and interest rate smoothing, which we elected to use. We expect to continue to make contributions to the pension plans in 2024 and future years that reflect the minimum requirements and discretionary amounts consistent with the amounts recovered in rates. Additional legislative or regulatory measures, as well as fluctuations in financial market conditions, may impact our funding requirements.

Due to the regulatory treatment of pension costs in Montana, pension costs for 2024 and 2023 were based on actual contributions to the plan. Annual contributions to each of the pension plans are as follows (in thousands):

	2024		2023
NorthWestern Energy Pension Plan	$ 8,122		$ 8,000

We estimate the plans will make future benefit payments to participants as follows (in thousands):

	Pension Benefits	Other Postretirement Benefits
2025	24,575	1,120
2026	25,611	986
2027	26,608	845
2028	27,326	841
2029	28,027	755
2030-2034	147,401	3,400

Defined Contribution Plan

Our defined contribution plan permits employees to defer receipt of compensation as provided in Section 401(k) of the Internal Revenue Code. Under the plan, employees may elect to direct a percentage of their gross compensation to the plan. We also contribute various percentages of employees' gross compensation to the plan. Company contributions for the years ended December 31, 2024 and 2023 were $11.6 million, $10.3 million, respectively.

(16) Stock-Based Compensation

Our employees participate in the NorthWestern Energy Group, Inc. Amended and Restated Equity Compensation Plan (ECP), which includes restricted stock awards and performance share awards. Stock-based compensation expense is allocated to us based on the outstanding awards held by our employees and our allocation of labor costs. We account for our share-based compensation arrangements by recognizing compensation costs for all share-based awards over the respective service period for employee services received in exchange for an award of equity or equity-based compensation. The compensation cost is based on the fair value of the grant on the date it was awarded.

We recognized total stock-based compensation expense of $2.8 million and $3.0 million for the years ended December 31, 2024 and 2023, respectively, and related income tax benefit of $(0.6) million, $(0.8) million for the years ended December 31, 2024 and 2023, respectively.

(17) Common Stock

We have 250,000,000 shares authorized consisting of 200,000,000 shares of common stock with a $0.01 par value and 50,000,000 shares of preferred stock with a $0.01 par value. We have 100 shares of common stock issued and outstanding.

Dividend Restrictions

Under various state regulatory agreements, debt agreements and the Federal Power Act, we have restrictions, including minimum equity ratios, that limit the amount of dividend distributions that can be made.

Pursuant to the MPSC regulatory agreement, if our secured credit ratings are above BBB- for S&P Global Ratings and Baa3 for Moody's Investor Services, we may declare or pay dividends as long as our common equity ratio is 40 percent or above. If our secured credit ratings are BBB- for S&P Global Ratings or Baa3 for Moody's Investor Services, we may declare or pay dividends as long as our common equity ratio is 43 percent or above. If our secured credit ratings fall below BBB- with S&P Global Ratings or Baa3 with Moody's Investor Services, we may not declare or pay dividends.

Our ability to pay dividends is also limited by the terms of various debt agreements, pursuant to which, we are required to maintain a debt to capitalization ratio of no more than 0.65 to 1.00.

As of December 31, 2024, approximately $784.6 million of our net assets were available for the payment of dividends under our most restrictive dividend restriction.

(18) Commitments and Contingencies

Qualifying Facilities Liability

Our QF liability primarily consists of unrecoverable costs associated with three contracts covered under the PURPA. These contracts require us to purchase minimum amounts of energy at prices ranging from $118 to $130 per MWH through 2029. As of December 31, 2024, our estimated gross contractual obligation related to these contracts was approximately $229.0 million through 2029. A portion of the costs incurred to purchase this energy is recoverable through rates, totaling approximately $205.8 million through 2029. As contractual obligations are settled, the related purchases and sales are recorded within Fuel, purchased power and direct transmission expense and Electric revenues in our Consolidated Statements of Income. The present value of the remaining liability is recorded in Other noncurrent liabilities in our Consolidated Balance Sheets. The following summarizes the change in the liability (in thousands):

	December 31,
	2024	2023
Beginning QF liability	$ 28,670	$ 49,728
Settlements(1)	(7,606)	(24,707)
Interest expense	2,434	3,649
Ending QF liability	$ 23,498	$ 28,670

The following summarizes the estimated gross contractual obligation less amounts recoverable through rates (in thousands):

	Gross Obligation	Recoverable Amounts	Net
2025	$ 60,360	$ 52,950	$ 7,410
2026	55,393	46,274	9,119
2027	56,665	46,668	9,997
2028	42,400	41,664	736
2029	14,134	18,231	(4,097)
Total(1)	$ 228,952	$ 205,787	$ 23,165

(1) This net unrecoverable amount represents the undiscounted difference between the total gross obligations and recoverable amounts. The ending QF liability in the table above represents the present value of this net unrecoverable amount.

Long Term Supply and Capacity Purchase Obligations

We have entered into various commitments, largely purchased power, electric transmission, coal and natural gas supply and natural gas transportation contracts. These commitments range from one to 24 years. Costs incurred under these contracts are included in Fuel, purchased power and direct transmission expense in the Consolidated Statements of Income and were approximately $189.5 million and $217.9 million for the years ended December 31, 2024 and 2023, respectively. As of December 31, 2024, our commitments under these contracts were $264.3 million in 2025, $312.2 million in 2026, $300.2 million in 2027, $298.9 million in 2028, $302.6 million in 2029, and $2.3 billion thereafter. These commitments are not reflected in our Consolidated Financial Statements.

Hydroelectric License Commitments

With the 2014 purchase of hydroelectric generating facilities and associated assets located in Montana, we assumed two Memoranda of Understanding (MOUs) existing with state, federal and private entities. The MOUs are periodically updated and renewed and require us to implement plans to mitigate the impact of the projects on fish, wildlife and their habitats, and to increase recreational opportunities. The MOUs were created to maximize collaboration between the parties and enhance the possibility to receive matching funds from relevant federal agencies. Under these MOUs, we have a remaining commitment to spend approximately $19.1 million between 2024 and 2040. These commitments are not reflected in our Consolidated Financial Statements.

ENVIRONMENTAL LIABILITIES AND REGULATION

Environmental Matters

The operation of electric generating, transmission and distribution facilities, and gas gathering, storage, transportation and distribution facilities, along with the development (involving site selection, environmental assessments, and permitting) and construction of these assets, are subject to extensive federal, state, and local environmental and land use laws and regulations. Our activities involve compliance with diverse laws and regulations that address emissions and impacts to the environment, including air and water, protection of natural resources, avian and wildlife. We monitor federal, state, and local environmental initiatives to determine potential impacts on our financial results. As new laws or regulations are implemented, our policy is to assess their applicability and implement the necessary modifications to our facilities or their operation to maintain ongoing compliance.

Our environmental exposure includes a number of components, including remediation expenses related to the cleanup of current or former properties, and costs to comply with changing environmental regulations related to our operations. At present, our environmental reserve is estimated to range between $6.2 million to $10.8 million. As of December 31, 2024, we had a reserve of approximately $8.1 million, which has not been discounted. Environmental costs are recorded when it is probable we are liable for the remediation and we can reasonably estimate the liability. We use a combination of site investigations and monitoring to formulate an estimate of environmental remediation costs for specific sites. Our monitoring procedures and development of actual remediation plans depend not only on site specific information but also on coordination with the different environmental regulatory agencies in our respective jurisdictions; therefore, while remediation exposure exists, it may be many years before costs are incurred.

The following summarizes the change in our environmental liability (in thousands):

	December 31,
	2024	2023
Liability at January 1,	$ 8,438	$ 8,858
Deductions	(416)	(1,084)
Charged to costs and expense	71	664
Liability at December 31,	$ 8,093	$ 8,438

We are permitted to recover the remediation costs related to certain environmental liabilities within rates. Over time, as costs become determinable, we may seek authorization to recover such costs in rates or seek insurance reimbursement as available and applicable; therefore, although we cannot guarantee regulatory recovery for all remediation costs, we do not expect these costs to have a material effect on our consolidated financial position or results of operations.

Global Climate Change - National and international actions have been initiated to address global climate change and the contribution of greenhouse gas (GHG) including, most significantly, carbon dioxide (CO2) and methane emissions from natural gas. These actions include legislative proposals, Executive, Congressional and EPA actions at the federal level, state level activity, investor activism and private party litigation relating to emissions. Coal-fired plants have come under particular scrutiny due to their level of emissions. We have joint ownership interests in one coal-fired electric generating plants, which is operated by Talen. We are responsible for our proportionate share of the capital and operating costs while being entitled to our proportionate share of the power generated.

EPA Rules - Congress has not passed any federal climate change legislation regarding GHG emissions from coal fired plants, and we cannot predict the timing or form of any potential legislation. Section 111(d) of the Clean Air Act (CAA) confers authority on EPA and the states to regulate emissions, including GHGs, from existing stationary sources. In April 2024, the EPA released final rules related to greenhouse gas (GHG) emission standards (GHG Rules) for existing coal-fired facilities and new coal and natural gas-fired facilities as well as final rules strengthening the MATS requirements (MATS Rules). In particular, the GHG Rules will (i) strengthen the current New Source Performance Standards for newly built fossil fuel-fired stationary combustion turbines (generally natural gas-fired); (ii) establish emission guidelines for states to follow in limiting carbon pollution from existing fossil fuel-fired steam generating electric generating units (including coal, oil and natural gas-fired units); and (iii) establish emission guidelines for large, frequently used existing fossil fuel-fired stationary combustion turbines (generally natural gas-fired). The MATS Rules will strengthen emission limits for acid gases, mercury, and other hazardous air pollutants from new and existing electric generating units. Compliance with the rules will require expensive upgrades at Colstrip Units 3 and 4 with proposed compliance dates that may not be achievable and / or require technology that is unproven, resulting in significant impacts to costs of the facilities. The final MATS and GHG Rules require compliance as early as 2027 and 2032, respectively.

Previous efforts by the EPA were met with extensive litigation, and this time is no different. We, along with many other utilities, electric cooperatives, organizations, and states, have petitioned for judicial review of the GHG and MATS Rules with the U.S. Court of Appeals for the D.C. Circuit. The United States Supreme Court denied the multiple stay requests related to the MATS Rule and the GHG Rule. The litigation on the merits continues for both the MATS and GHG rules in the D.C. Circuit Court of Appeals, and decisions are expected in 2025 unless the EPA reconsiders the underlying rules. If the MATS Rules and GHG Rules are implemented, it would result in additional material compliance costs. We will continue working with federal and state regulatory authorities, other utilities, and stakeholders to seek relief from the MATS and GHG regulations that, in our view, disproportionately impact customers in our region.

These GHG Rules and MATS Rules as well as future additional environmental requirements - federal or state - could cause us to incur material costs of compliance, increase our costs of procuring electricity, decrease transmission revenue and impact cost recovery. Technology to efficiently capture, remove and/or sequester such GHG emissions or hazardous air pollutants may not be available within a timeframe consistent with the implementation of any such requirements.

Regional Haze Rules - In January 2017, the EPA published amendments to the requirements under the CAA for state plans for protection of visibility - regional haze rules. Among other things, these amendments revised the process and requirements for the state implementation plans and extended the due date for the next periodic comprehensive regional haze state implementation plan revisions from 2018 to 2021.

The state of Montana has developed and submitted to the EPA, for its approval, their respective State Implementation Plan (SIP) for Regional Haze compliance. While the state of Montana did not meet the EPA’s July 31, 2021 submission deadline, it was submitted in 2022. The Montana SIP as drafted and submitted to EPA does not call for additional controls for our interest in Colstrip Unit 4. Until the SIP is finalized and approved by EPA, the potential remains that installation of additional emissions controls might be required at the Colstrip facility

Jointly Owned Plants - We have joint ownership in a generation plant located in Montana that is or may become subject to the various regulations discussed above that have been or may be issued or proposed.

Other - We continue to manage equipment containing polychlorinated biphenyl (PCB) oil in accordance with the EPA's Toxic Substance Control Act regulations. We will continue to use certain PCB-contaminated equipment for its remaining useful life and will, thereafter, dispose of the equipment according to pertinent regulations that govern the use and disposal of such equipment.

We routinely engage the services of a third-party environmental consulting firm to assist in performing a comprehensive evaluation of our environmental reserve. Based upon information available at this time, we believe that the current environmental reserve properly reflects our remediation exposure for the sites currently and previously owned by us. The portion of our environmental reserve applicable to site remediation may be subject to change as a result of the following uncertainties:

• We may not know all sites for which we are alleged or will be found to be responsible for remediation; and

• Absent performance of certain testing at sites where we have been identified as responsible for remediation, we cannot estimate with a reasonable degree of certainty the total costs of remediation.

LEGAL PROCEEDINGS

State of Montana - Riverbed Rents

On April 1, 2016, the State of Montana (State) filed a complaint on remand (the State’s Complaint) with the Montana First Judicial District Court (State District Court), naming us, along with Talen Montana, LLC (Talen) as defendants. The State claimed it owns the riverbeds underlying 10 of our, and formerly Talen’s, hydroelectric facilities (dams, along with reservoirs and tailraces) on the Missouri, Madison and Clark Fork Rivers, and seeks rents for Talen’s and our use and occupancy of such lands. The facilities at issue include the Hebgen, Madison, Hauser, Holter, Black Eagle, Rainbow, Cochrane, Ryan, and Morony facilities on the Missouri and Madison Rivers and the Thompson Falls facility on the Clark Fork River. We acquired these facilities from Talen in November 2014.

The litigation has a long prior history. In 2012, the United States Supreme Court issued a decision holding that the Montana Supreme Court erred in not considering a segment-by-segment approach to determine navigability and relying on present day recreational use of the rivers. It also held that what it referred to as the Great Falls Reach “at least from the head of the first waterfall to the foot of the last” was not navigable for title purposes, and thus the State did not own the riverbeds in that segment. The United States Supreme Court remanded the case to the Montana Supreme Court for further proceedings not inconsistent with its opinion. Following the 2012 remand, the case laid dormant for four years until the State’s Complaint was filed with the State District Court. On April 20, 2016, we removed the case from State District Court to the United States District Court for the District of Montana (Federal District Court). On August 1, 2018, the Federal District Court granted our and Talen’s motions to dismiss the State’s Complaint as it pertains to the navigability of the riverbeds associated with four of our hydroelectric facilities near Great Falls. A bench trial before the Federal District Court commenced January 4, 2022, and concluded on January 18, 2022, which addressed the issue of navigability concerning our other six facilities. On August 25, 2023, the Federal District Court issued its Findings of Fact, Conclusions of Law, and Order (the "Order"), which found all but one of the segments of the riverbeds in dispute not navigable, and thus not owned by the State of Montana. The one segment found navigable, and thus owned by the State, was the segment on which the Black Eagle development was located. The State filed a motion to pursue an interlocutory appeal of the Order, and on January 2, 2024, the Federal District Court certified the Order for appeal to the 9th Circuit Court of Appeals. The appeal was argued on January 15, 2025, and we await the court's disposition. Damages were bifurcated by agreement and will be tried separately for the Black Eagle segment, and any other segments found navigable, should the State prevail on appeal.

We dispute the State’s claims and intend to continue to vigorously defend the lawsuit. If the Federal District Court calculates damages as the State District Court did in 2008, we do not anticipate the resulting annual rent for the Black Eagle segment would have a material impact to our financial position or results of operations. We anticipate that any obligation to pay the State rent for use and occupancy of the riverbeds would be recoverable in rates from customers, although there can be no assurances that the MPSC would approve any such recovery.

Yellowstone County Generating Station Air Permit

On October 21, 2021, the Montana Environmental Information Center and the Sierra Club filed a lawsuit in Montana State District Court, against the Montana Department of Environmental Quality (MDEQ) and NorthWestern, alleging that the environmental analysis conducted by MDEQ prior to issuance of the YCGS air quality construction permit was inadequate. On April 4, 2023, the Montana District Court issued an order finding MDEQ's environmental analysis was deficient in not addressing exterior lighting and greenhouse gases and remanded it back to MDEQ to address the deficiencies and vacated the YCGS air quality permit pending that remand. As a result of the vacatur of the permit, we paused construction. On June 8, 2023, the Montana District Court granted our motion to stay the order vacating the air quality permit pending the outcome of our appeal to the Montana Supreme Court. We recommenced YCGS construction in June 2023 and placed the plant in service in October 2024. On January 3, 2025, the Montana Supreme Court ordered that the YCGS air quality permit be reinstated. The Court remanded the matter back to MDEQ for supplemental analysis regarding lighting and greenhouse gas emissions in Montana. YCGS is commercially operable with the reinstated air quality permit.

Other Legal Proceedings

We are also subject to various other legal proceedings, governmental audits and claims that arise in the ordinary course of business. In our opinion, the amount of ultimate liability with respect to these other actions will not materially affect our financial position, results of operations, or cash flows.

(19) Revenue from Contracts with Customers

Accounting Policy

Our revenues are primarily from tariff based sales. We provide gas and/or electricity to customers under these tariffs without a defined contractual term (at-will). As the revenue from these arrangements is equivalent to the electricity or gas supplied and billed in that period (including estimated billings), there will not be a shift in the timing or pattern of revenue recognition for such sales. We have also completed the evaluation of our other revenue streams, including those tied to longer term contractual commitments. These revenue streams have performance obligations that are satisfied at a point in time, and do not have a shift in the timing or pattern of revenue recognition.

Customers are billed monthly on a cycle basis. To match revenues with associated expenses, we accrue unbilled revenues for electric and natural gas services delivered to customers, but not yet billed at month-end.

Nature of Goods and Services

We currently provide retail electric and natural gas services to three primary customer classes. Our largest customer class consists of residential customers, which include single private dwellings and individual apartments. Our commercial customers consist primarily of main street businesses, and our industrial customers consist primarily of manufacturing and processing businesses that turn raw materials into products.

Electric Segment - Our regulated electric utility business primarily provides generation, transmission, and distribution services to our customers. We recognize revenue when electricity is delivered to the customer. Payments on our tariff based sales are generally due in 20-30 days after the billing date.

Natural Gas Segment - Our regulated natural gas utility business primarily provides production, storage, transmission, and distribution services to our customers. We recognize revenue when natural gas is delivered to the customer. Payments on our tariff based sales are generally due in 20-30 days after the billing date.

Disaggregation of Revenue

The following tables disaggregate our revenue for the twelve months ended by major source and customer class (in millions):

December 31, 2024	Electric	Natural Gas	Total
Residential	$ 398.8	$ 110.2	$ 509.0
Commercial	409.0	59.9	468.9
Industrial	46.6	1.0	47.6
Lighting, governmental, irrigation, and interdepartmental	29.5	1.4	30.9
Total Retail Revenues	883.9	172.5	1,056.4
Regulatory Amortization	21.1	14.6	35.7
Transmission	97.0	—	97.0
Wholesale and other	8.2	37.1	45.3
Total Revenues	$ 1,010.2	$ 224.2	$ 1,234.4

December 31, 2023	Electric	Natural Gas	Total
Residential	$ 408.3	$ 136.1	$ 544.4
Commercial	431.4	73.7	505.1
Industrial	46.0	1.4	47.4
Lighting, governmental, irrigation, and interdepartmental	30.0	1.7	31.7
Total Retail Revenues	915.7	212.9	1,128.6
Regulatory Amortization	(103.8)	(15.2)	(119.0)
Transmission	78.4	—	78.4
Wholesale and other	8.0	40.2	48.2
Total Revenues	$ 898.3	$ 237.9	$ 1,136.2

(20) Related Party Transactions and Shared Services

Our parent, NorthWestern Energy Group, Inc., is organized as a holding company. As part of a holding company we receive services and share costs with Northwestern Energy Group, Inc., and its other subsidiaries pursuant to an Intercompany Services Agreement (ISA) that became effective in 2023. The ISA was approved by the MPSC. We employ all or substantially all of the employees of NorthWestern Energy Group, Inc. and its subsidiaries and, in accordance with the ISA, will provide all employment related services to the parties to the ISA. Pursuant to the ISA, all rendered services are at cost. For the year ended December 31, 2024, the total amount of payroll related services provided to NorthWestern Energy Public Service Corporation, a direct wholly-owned subsidiary of NorthWestern Energy Group, Inc., was $39.3 million.

Additionally, pursuant to the ISA, when utility-related operating, administrative, and general costs are attributable to more than one entity within the holding company structure and are unable to be direct charged (Shared OA&G Costs), these costs will be allocated amongst the entities pursuant to a Cost Allocation Manual. The nature of these Shared OA&G Costs includes operations supervision and engineering, energy supply marketing, networking communications, information technology, human resources, accounting, legal, and other such administrative costs.

The services provided under the ISA are settled in cash amongst the parties each month.

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

STATEMENTS OF ACCUMULATED COMPREHENSIVE INCOME, COMPREHENSIVE INCOME, AND HEDGING ACTIVITIES
Report in columns (b),(c),(d) and (e) the amounts of accumulated other comprehensive income items, on a net-of-tax basis, where appropriate. Report in columns (f) and (g) the amounts of other categories of other cash flow hedges. For each category of hedges that have been accounted for as "fair value hedges", report the accounts affected and the related amounts in a footnote. Report data on a year-to-date basis.
Line No.	Item (a)	Unrealized Gains and Losses on Available-For-Sale Securities (b)	Minimum Pension Liability Adjustment (net amount) (c)	Foreign Currency Hedges (d)	Other Adjustments (e)	Other Cash Flow Hedges Interest Rate Swaps (f)	Other Cash Flow Hedges [Specify] (g)	Totals for each category of items recorded in Account 219 (h)	Net Income (Carried Forward from Page 116, Line 78) (i)	Total Comprehensive Income (j)
1	Balance of Account 219 at Beginning of Preceding Year		535,470		1,434,774	7,675,908		5,705,664
2	Preceding Quarter/Year to Date Reclassifications from Account 219 to Net Income		261,851			452,130		190,279
3	Preceding Quarter/Year to Date Changes in Fair Value				2,385			2,385
4	Total (lines 2 and 3)		261,851		2,385	452,130		192,664	194,131,555	194,324,219
5	Balance of Account 219 at End of Preceding Quarter/Year		273,619		1,437,159	7,223,778		5,513,000
6	Balance of Account 219 at Beginning of Current Year		273,619		1,437,159	7,223,778		5,513,000
7	Current Quarter/Year to Date Reclassifications from Account 219 to Net Income		318,221			452,130		133,909
8	Current Quarter/Year to Date Changes in Fair Value				4,302			4,302
9	Total (lines 7 and 8)		318,221		4,302	452,130		129,607	180,078,441	180,208,048
10	Balance of Account 219 at End of Current Quarter/Year		44,602		1,432,857	6,771,648		5,383,393

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

SUMMARY OF UTILITY PLANT AND ACCUMULATED PROVISIONS FOR DEPRECIATION. AMORTIZATION AND DEPLETION
Report in Column (c) the amount for electric function, in column (d) the amount for gas function, in column (e), (f), and (g) report other (specify) and in column (h) common function.
Line No.	Classification (a)	Total Company For the Current Year/Quarter Ended (b)	Electric (c)	Gas (d)	Other (Specify) (e)	Other (Specify) (f)	Other (Specify) (g)	Common (h)
1	UtilityPlantAbstract UTILITY PLANT
2	UtilityPlantInServiceAbstract In Service
3	UtilityPlantInServiceClassified Plant in Service (Classified)	6,430,468,639	4,954,047,833	1,264,376,272	(b) 1,730,244	0	0	210,314,290
4	UtilityPlantInServicePropertyUnderCapitalLeases Property Under Capital Leases	40,943,218	0	0	0	(c) 40,209,537	(d) 733,681	0
5	UtilityPlantInServicePlantPurchasedOrSold Plant Purchased or Sold	0	0	0	0	0	0	0
6	UtilityPlantInServiceCompletedConstructionNotClassified Completed Construction not Classified	0	0	0	0	0	0	0
7	UtilityPlantInServiceExperimentalPlantUnclassified Experimental Plant Unclassified	4,798,750	4,798,750	0	0	0	0	0
8	UtilityPlantInServiceClassifiedAndUnclassified Total (3 thru 7)	6,476,210,606	4,958,846,583	1,264,376,272	1,730,244	40,209,537	733,681	210,314,290
9	UtilityPlantLeasedToOthers Leased to Others	0	0	0	0	0	0	0
10	UtilityPlantHeldForFutureUse Held for Future Use	4,191,930	4,162,063	29,867	0	0	0	0
11	ConstructionWorkInProgress Construction Work in Progress	125,080,799	88,683,342	21,021,804	0	0	0	15,375,653
12	UtilityPlantAcquisitionAdjustment Acquisition Adjustments	656,318,593	656,318,593	0	0	0	0	0
13	UtilityPlantAndConstructionWorkInProgress Total Utility Plant (8 thru 12)	7,261,801,927	5,708,010,581	1,285,427,943	1,730,244	40,209,537	733,680	225,689,943
14	AccumulatedProvisionForDepreciationAmortizationAndDepletionOfPlantUtility Accumulated Provisions for Depreciation, Amortization, & Depletion	2,449,906,491	1,897,256,810	450,629,448	1,164,154	37,193,802	0	63,662,277
15	UtilityPlantNet Net Utility Plant (13 less 14)	4,811,895,436	3,810,753,771	834,798,495	566,090	3,015,735	733,680	162,027,666
16	DetailOfAccumulatedProvisionsForDepreciationAmortizationAndDepletionAbstract DETAIL OF ACCUMULATED PROVISIONS FOR DEPRECIATION, AMORTIZATION AND DEPLETION
17	AccumulatedProvisionForDepreciationAmortizationAndDepletionUtilityPlantInServiceAbstract In Service:
18	DepreciationUtilityPlantInService Depreciation	2,140,108,808	1,673,739,727	386,875,220	1,164,154	37,193,802	0	41,135,905
19	AmortizationAndDepletionOfProducingNaturalGasLandAndLandRightsutilityPlantInService Amortization and Depletion of Producing Natural Gas Land and Land Rights	55,968,483	0	55,968,483	0	0	0	0
20	AmortizationOfUndergroundStorageLandAndLandRightsutilityPlantInService Amortization of Underground Storage Land and Land Rights
21	AmortizationOfOtherUtilityPlantUtilityPlantInService Amortization of Other Utility Plant	60,121,026	(a) 29,808,909	7,785,745	0	0	0	22,526,372
22	DepreciationAmortizationAndDepletionUtilityPlantInService Total in Service (18 thru 21)	2,256,198,317	1,703,548,636	450,629,448	1,164,154	37,193,802	0	63,662,277
23	DepreciationAmortizationAndDepletionUtilityPlantLeasedToOthersAbstract Leased to Others
24	DepreciationUtilityPlantLeasedToOthers Depreciation
25	AmortizationAndDepletionUtilityPlantLeasedToOthers Amortization and Depletion
26	DepreciationAmortizationAndDepletionUtilityPlantLeasedToOthers Total Leased to Others (24 & 25)
27	DepreciationAndAmortizationUtilityPlantHeldForFutureUseAbstract Held for Future Use
28	DepreciationUtilityPlantHeldForFutureUse Depreciation
29	AmortizationUtilityPlantHeldForFutureUse Amortization
30	DepreciationAndAmortizationUtilityPlantHeldForFutureUse Total Held for Future Use (28 & 29)
31	AbandonmentOfLeases Abandonment of Leases (Natural Gas)
32	AmortizationOfPlantAcquisitionAdjustment Amortization of Plant Acquisition Adjustment	193,708,174	193,708,174
33	AccumulatedProvisionForDepreciationAmortizationAndDepletionOfPlantUtility Total Accum Prov (equals 14) (22,26,30,31,32)	2,449,906,491	1,897,256,810	450,629,448	1,164,154	37,193,802	0	63,662,277

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

FOOTNOTE DATA

(a) Concept: AmortizationOfOtherUtilityPlantUtilityPlantInService

Amortization of other Montna Electric Plant was $27,003,078 for 2023.

(b) Concept: UtilityPlantInServiceClassified

This column represents regulated propane.

This column represents an electric default supply capacity and energy sales agreement classified as a capital lease.

(d) Concept: UtilityPlantInServicePropertyUnderCapitalLeases

This column represents our right of use (operating lease) assets.

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

NUCLEAR FUEL MATERIALS (Account 120.1 through 120.6 and 157)
Report below the costs incurred for nuclear fuel materials in process of fabrication, on hand, in reactor, and in cooling; owned by the respondent. If the nuclear fuel stock is obtained under leasing arrangements, attach a statement showing the amount of nuclear fuel leased, the quantity used and quantity on hand, and the costs incurred under such leasing arrangements.
Line No.	Description of item (a)	Balance Beginning of Year (b)	Changes during Year Additions (c)	Changes during Year Amortization (d)	Changes during Year Other Reductions (Explain in a footnote) (e)	Balance End of Year (f)
1	Nuclear Fuel in process of Refinement, Conv, Enrichment & Fab (120.1)
2	Fabrication
3	Nuclear Materials
4	Allowance for Funds Used during Construction
5	(Other Overhead Construction Costs, provide details in footnote)
6	SUBTOTAL (Total 2 thru 5)
7	Nuclear Fuel Materials and Assemblies
8	In Stock (120.2)
9	In Reactor (120.3)
10	SUBTOTAL (Total 8 & 9)
11	Spent Nuclear Fuel (120.4)
12	Nuclear Fuel Under Capital Leases (120.6)
13	(Less) Accum Prov for Amortization of Nuclear Fuel Assem (120.5)
14	TOTAL Nuclear Fuel Stock (Total 6, 10, 11, 12, less 13)
15	Estimated Net Salvage Value of Nuclear Materials in Line 9
16	Estimated Net Salvage Value of Nuclear Materials in Line 11
17	Est Net Salvage Value of Nuclear Materials in Chemical Processing
18	Nuclear Materials held for Sale (157)
19	Uranium
20	Plutonium
21	Other (Provide details in footnote)
22	TOTAL Nuclear Materials held for Sale (Total 19, 20, and 21)

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

ELECTRIC PLANT IN SERVICE (Account 101, 102, 103 and 106)
Report below the original cost of electric plant in service according to the prescribed accounts. In addition to Account 101, Electric Plant in Service (Classified), this page and the next include Account 102, Electric Plant Purchased or Sold; Account 103, Experimental Electric Plant Unclassified; and Account 106, Completed Construction Not Classified-Electric. Include in column (c) or (d), as appropriate, corrections of additions and retirements for the current or preceding year. For revisions to the amount of initial asset retirement costs capitalized, included by primary plant account, increases in column (c) additions and reductions in column (e) adjustments. Enclose in parentheses credit adjustments of plant accounts to indicate the negative effect of such accounts. Classify Account 106 according to prescribed accounts, on an estimated basis if necessary, and include the entries in column (c). Also to be included in column (c) are entries for reversals of tentative distributions of the prior year reported in column (b). Likewise, if the respondent has a significant amount of plant retirements which have not been classified to primary accounts at the end of the year, include in column (d) a tentative distribution of such retirements, on an estimated basis, with appropriate contra entry to the account for accumulated depreciation provision. Include also in column (d) distributions of these tentative classifications in columns (c) and (d), including the reversals of the prior years tentative account distributions of these amounts. Careful observance of the above instructions and the texts of Accounts 101 and 106 will avoid serious omissions of the reported amount of respondent’s plant actually in service at end of year. Show in column (f) reclassifications or transfers within utility plant accounts. Include also in column (f) the additions or reductions of primary account classifications arising from distribution of amounts initially recorded in Account 102, include in column (e) the amounts with respect to accumulated provision for depreciation, acquisition adjustments, etc., and show in column (f) only the offset to the debits or credits distributed in column (f) to primary account classifications. For Account 399, state the nature and use of plant included in this account and if substantial in amount submit a supplementary statement showing subaccount classification of such plant conforming to the requirement of these pages. For each amount comprising the reported balance and changes in Account 102, state the property purchased or sold, name of vendor or purchase, and date of transaction. If proposed journal entries have been filed with the Commission as required by the Uniform System of Accounts, give also date.
Line No.	Account (a)	Balance Beginning of Year (b)	Additions (c)	Retirements (d)	Adjustments (e)	Transfers (f)	Balance at End of Year (g)
1	1. INTANGIBLE PLANT
2	(301) Organization	(a) 19,995	0	0	0	0	19,995
3	(302) Franchise and Consents	21,479,709	977,482	0	0	0	22,457,191
4	(303) Miscellaneous Intangible Plant	18,573,065	1,156,510	868,284	1,965,341	155	16,896,105
5	TOTAL Intangible Plant (Enter Total of lines 2, 3, and 4)	40,072,769	2,133,992	868,284	1,965,341	155	39,373,291
6	2. PRODUCTION PLANT
7	A. Steam Production Plant
8	(310) Land and Land Rights	812,637	0	0	366,511	0	446,126
9	(311) Structures and Improvements	55,955,753	163,465	9,381	27,741,805	0	28,368,032
10	(312) Boiler Plant Equipment	243,869,899	4,045,363	203,222	201,277,662	0	46,434,378
11	(313) Engines and Engine-Driven Generators	0	0	0	0	0	0
12	(314) Turbogenerator Units	48,711,960	1,375,076	175,670	27,642,498	0	22,268,868
13	(315) Accessory Electric Equipment	15,221,201	657,688	0	13,144,728	0	2,734,161
14	(316) Misc. Power Plant Equipment	26,232,157	0	0	3,284,483	0	22,947,674
15	(317) Asset Retirement Costs for Steam Production	23,377,391	647,761	0	2,023,902	0	20,705,728
16	TOTAL Steam Production Plant (Enter Total of lines 8 thru 15)	414,180,998	5,593,832	388,273	275,481,590	0	143,904,967
17	B. Nuclear Production Plant
18	(320) Land and Land Rights						0
19	(321) Structures and Improvements						0
20	(322) Reactor Plant Equipment						0
21	(323) Turbogenerator Units						0
22	(324) Accessory Electric Equipment						0
23	(325) Misc. Power Plant Equipment						0
24	(326) Asset Retirement Costs for Nuclear Production						0
25	TOTAL Nuclear Production Plant (Enter Total of lines 18 thru 24)	0	0	0	0	0	0
26	C. Hydraulic Production Plant
27	(330) Land and Land Rights	5,958,416	380,876	0	0	0	6,339,292
28	(331) Structures and Improvements	130,050,562	997,969	412,712	0	0	130,635,819
29	(332) Reservoirs, Dams, and Waterways	195,161,800	11,822,751	861,718	0	0	206,122,833
30	(333) Water Wheels, Turbines, and Generators	189,566,172	15,796,544	3,690,303	0	0	201,672,413
31	(334) Accessory Electric Equipment	94,867,869	718,297	40,147	0	0	95,546,019
32	(335) Misc. Power Plant Equipment	20,768,388	111,492	0	0	0	20,879,880
33	(336) Roads, Railroads, and Bridges	3,069,284	838,729	0	0	0	3,908,013
34	(337) Asset Retirement Costs for Hydraulic Production	0					0
35	TOTAL Hydraulic Production Plant (Enter Total of lines 27 thru 34)	639,442,491	30,666,658	5,004,880	0	0	665,104,269
36	D. Other Production Plant
37	(340) Land and Land Rights	4,080,564	0	0	261,179	0	3,819,385
38	(341) Structures and Improvements	85,633,339	64,396,799	0	26,183,867	0	123,846,271
39	(342) Fuel Holders, Products, and Accessories	26,513,798	13,469,300	0	5,283,753	0	34,699,345
40	(343) Prime Movers	218,043,434	92,284,646	4,563,355	127,482,377	0	178,282,348
41	(344) Generators	143,520,064	60,707,931	0	87,862,628	0	116,365,367
42	(345) Accessory Electric Equipment	27,024,837	32,957,966	0	7,860,833	0	52,121,970
43	(346) Misc. Power Plant Equipment	51,706,021	32,683,010	0	22,614,998	0	61,774,033
44	(347) Asset Retirement Costs for Other Production	5,038,356	0	0	1,351,540	0	3,686,816
44.1	(348) Energy Storage Equipment - Production	0					0
45	TOTAL Other Prod. Plant (Enter Total of lines 37 thru 44)	561,560,413	296,499,654	4,563,355	278,901,177	0	574,595,535
46	TOTAL Prod. Plant (Enter Total of lines 16, 25, 35, and 45)	1,615,183,902	332,760,143	9,956,508	554,382,766	0	1,383,604,771
47	3. Transmission Plant
48	(350) Land and Land Rights	44,840,703	499,928	0	1,873,381	158	43,467,408
48.1	(351) Energy Storage Equipment - Transmission	0	0	0	0	0	0
49	(352) Structures and Improvements	77,148,168	22,864,515	20,028	13,539,688	123,811	86,576,778
50	(353) Station Equipment	474,649,282	23,688,222	3,481,286	109,647,684	258,618	384,949,916
51	(354) Towers and Fixtures	30,640,142	0	0	0	0	30,640,142
52	(355) Poles and Fixtures	557,880,440	30,225,010	5,001,219	63,569,429	104,122	519,430,680
53	(356) Overhead Conductors and Devices	218,933,153	4,216,428	272,972	33,574,139	71,602	189,374,072
54	(357) Underground Conduit	778,680	0	0	640,802	0	137,878
55	(358) Underground Conductors and Devices	6,668,974	0	0	4,707,010	0	1,961,964
56	(359) Roads and Trails	4,043,372	0	0	0	13,223	4,056,595
57	(359.1) Asset Retirement Costs for Transmission Plant	0	0	0	0	0	0
58	TOTAL Transmission Plant (Enter Total of lines 48 thru 57)	1,415,582,914	81,494,103	8,775,505	227,552,133	153,946	1,260,595,433
59	4. Distribution Plant
60	(360) Land and Land Rights	15,419,098	0	0	639,546	46,824	14,732,728
61	(361) Structures and Improvements	45,713,144	5,424,727	16,974	1,532,776	3,176,646	52,764,767
62	(362) Station Equipment	311,536,494	20,268,292	2,882,467	49,012,947	3,263,051	276,646,321
63	(363) Energy Storage Equipment – Distribution	0	8,867,100	0	0	0	8,867,100
64	(364) Poles, Towers, and Fixtures	451,616,004	26,671,678	1,467,629	61,524,411	94,417	415,390,059
65	(365) Overhead Conductors and Devices	179,629,573	10,239,970	119,555	23,628,714	30,588	166,151,862
66	(366) Underground Conduit	194,038,626	13,480,987	909	11,752,160	0	195,766,544
67	(367) Underground Conductors and Devices	348,012,344	17,202,844	284,015	65,951,874	5,874	298,985,173
68	(368) Line Transformers	323,523,481	18,420,268	1,985,677	46,127,334	0	293,830,738
69	(369) Services	210,027,103	14,204,001	205,012	23,491,076	0	200,535,016
70	(370) Meters	101,722,534	22,882,505	17,192,354	14,732,736	0	92,679,949
71	(371) Installations on Customer Premises	735,362	0	0	735,362	0	0
72	(372) Leased Property on Customer Premises	0	0	0	0	0	0
73	(373) Street Lighting and Signal Systems	94,008,406	1,038,516	348,264	10,910,313	0	83,788,345
74	(374) Asset Retirement Costs for Distribution Plant	0	0	0	0	0	0
75	TOTAL Distribution Plant (Enter Total of lines 60 thru 74)	2,275,982,170	158,700,889	24,502,856	310,039,248	2,353	2,100,138,602
76	5. REGIONAL TRANSMISSION AND MARKET OPERATION PLANT
77	(380) Land and Land Rights	0	0	0	0	0	0
78	(381) Structures and Improvements	0	0	0	0	0	0
79	(382) Computer Hardware	0	0	0	0	0	0
80	(383) Computer Software	0	0	0	0	0	0
81	(384) Communication Equipment	0	0	0	0	0	0
82	(385) Miscellaneous Regional Transmission and Market Operation Plant	0	0	0	0	0	0
83	(386) Asset Retirement Costs for Regional Transmission and Market Oper	0	0	0	0	0	0
84	TOTAL Transmission and Market Operation Plant (Total lines 77 thru 83)	0	0	0	0	0	0
85	6. General Plant
86	(389) Land and Land Rights	795,141	0	0	105,508	0	689,633
87	(390) Structures and Improvements	12,460,136	0	11,999	1,835,049	10,885	10,602,203
88	(391) Office Furniture and Equipment	2,551,756	209,330	2,303	85,089	548,073	3,221,767
89	(392) Transportation Equipment	85,109,921	3,704,625	1,692,245	17,283,519	0	69,838,782
90	(393) Stores Equipment	1,191,168	23,991	0	36,060	0	1,179,099
91	(394) Tools, Shop and Garage Equipment	13,186,941	671,672	219,805	2,091,100	1,699	11,549,407
92	(395) Laboratory Equipment	1,033,178	0	5,752	0	0	1,027,426
93	(396) Power Operated Equipment	7,980,201	58,350	150,312	938,986	0	6,949,253
94	(397) Communication Equipment	60,929,306	425,144	730	2,679,613	4,351,053	63,025,160
95	(398) Miscellaneous Equipment	2,122,711	122,721	0	0	7,574	2,253,006
96	SUBTOTAL (Enter Total of lines 86 thru 95)	187,360,459	5,215,834	2,083,147	25,054,924	4,897,514	170,335,736
97	(399) Other Tangible Property	0	0	0	0	0	0
98	(399.1) Asset Retirement Costs for General Plant	0	0	0	0	0	0
99	TOTAL General Plant (Enter Total of lines 96, 97, and 98)	187,360,459	5,215,834	2,083,147	25,054,924	4,897,514	170,335,736
100	TOTAL (Accounts 101 and 106)	5,534,182,214	580,304,962	46,186,300	1,118,994,413	4,741,370	4,954,047,833
101	(102) Electric Plant Purchased (See Instr. 8)	0	0	0	0	0	0
102	(Less) (102) Electric Plant Sold (See Instr. 8)	0	0	0	0	0	0
103	(103) Experimental Plant Unclassified	4,798,750	0	0	0	0	4,798,750
104	TOTAL Electric Plant in Service (Enter Total of lines 100 thru 103)	5,538,980,964	580,304,962	46,186,300	(b) 1,118,994,413	4,741,370	4,958,846,583

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

FOOTNOTE DATA

(a) Concept: Organization

Montana Only Operations


Line	Account	Beginning of Year

No.	(a)	(g)
1	1. INTANGIBLE PLANT
2	(301) Organization	19,995
3	(302) Franchises and Consents	21,479,709
4	(303) Miscellaneous Intangible Plant	16,607,725
5	TOTAL Intangible Plant (Enter Total of lines 2, 3, and4)	38,107,429
6	2. PRODUCTION PLANT
7	A. Steam Production Plant
8	(310) Land and Land Rights	446,126
9	(311) Structures and Improvements	28,213,948
10	(312) Boiler Plant Equipment	42,592,236
11	(313) Engines and Engine-Driven Generators
12	(314) Turbogenerator Units	21,069,461
13	(315) Accessory Electric Equipment	2,076,473
14	(316) Misc. Power Plant Equipment	22,947,674
15	(317) Asset Retirement Costs for Steam	21,353,489
16	TOTAL Steam Production Plant (Enter Total of lines 8 thru 14)	138,699,407
17	B. Nuclear Production Plant
18	(320) Land and Land Rights
19	(321) Structures and Improvements
20	(322) Reactor Plant Equipment
21	(323) Turbogenerator Units
22	(324) Accessory Electric Equipment
23	(325) Misc. Power Plant Equipment
24	TOTAL Nuclear Production Plant (Enter Total of lines 17 thru 22)
25	C. Hydraulic Production Plant
26	(330) Land and Land Rights	5,958,416
27	(331) Structures and Improvements	130,050,562
28	(332) Reservoirs, Dams, and Waterways	195,161,800

29	(333) Water Wheels, Turbines, and Generators	189,566,172
30	(334) Accessory Electric Equipment	94,867,869
31	(335) Misc. Power Plant Equipment	20,768,388
32	(336) Roads, Railroads, and Bridges	3,069,284
33	TOTAL Hydraulic Production Plant (Enter Total of lines 25 thru 31)	639,442,491
34	D. Other Production Plant
35	(340) Land and Land Rights	3,819,385
36	(341) Structures and Improvements	59,449,471
37	(342) Fuel Holders, Products, and	21,230,045
	Accessories
38	(343) Prime Movers	90,561,056
39	(344) Generators	55,657,436
40	(345) Accessory Electric Equipment	19,164,004
41	(346) Misc. Power Plant Equipment	29,091,023
42	(347) Asset Retirement Costs for Other	3,686,815
	Production
43	TOTAL Other Production Plant (Enter Total of lines 34 thru 40)	282,659,235
44	TOTAL Production Plant (Enter Total of lines 15, 23, 32, and 41)	1,060,801,133
45	3. TRANSMISSION PLANT
46	(350) Land and Land Rights	42,967,324
47	(352) Structures and Improvements	63,608,479
48	(353) Station Equipment	365,001,598
49	(354) Towers and Fixtures	30,640,142
50	(355) Poles and Fixtures	494,311,006
51	(356) Overhead Conductors and Devices	185,359,014
52	(357) Underground Conduit	137,878
53	(358) Underground Conductors and Devices	1,961,964
54	(359) Roads and Trails	4,043,372
55	TOTAL Transmission Plant (Enter Total of lines 44 thru 52)	1,188,030,777
56	4. DISTRIBUTION PLANT
57	(360) Land and Land Rights	14,779,553
58	(361) Structures and Improvements	44,180,370
59	(362) Station Equipment	262,523,547
60	(363) Storage Battery Equipment

61	(364) Poles, Towers, and Fixtures	390,091,593
62	(365) Overhead Conductors and Devices	156,000,859
63	(366) Underground Conduit	182,286,466
64	(367) Underground Conductors and Devices	282,060,470
65	(368) Line Transformers	277,396,148
66	(369) Services	186,536,026
67	(370) Meters	86,989,799
68	(371) Installations on Customer Premises
69	(372) Leased Property on Customer Premises
70	(373&388) Street Lighting and Signal Systems	83,098,093
71	(374) Asset Retirement Costs for Distribution Plant
72	TOTAL Distribution Plant (Enter Total of lines 55 thru 68)	1,965,942,924
73	5. GENERAL PLANT
74	(389) Land and Land Rights	689,633
75	(390) Structures and Improvements	10,625,088
76	(391) Office Furniture and Equipment	2,466,667
77	(392) Transportation Equipment	67,826,402
78	(393) Stores Equipment	1,155,108
79	(394) Tools, Shop and Garage Equipment	11,095,842
80	(395) Laboratory Equipment	1,033,178
81	(396) Power Operated Equipment	7,041,215
82	(397) Communication Equipment	58,249,692
83	(398) Miscellaneous Equipment	2,122,710
84	SUBTOTAL (Enter Total of lines 71 thru 80)	162,305,535
85	(399) Other Tangible Property
86	TOTAL General Plant (Enter Total of lines 81 and 82)	162,305,535
87	TOTAL (Accounts 101 and 106)	4,415,187,798
88	(102) Electric Plant Purchased (See Instr. 8)
89	(Less) (102) Electric Plant Sold (See Instr. 8)
90	(103) Experimental Plant Unclassified	4,798,750
91	TOTAL Electric Plant in Service(Enter Total of lines 84 thru 87)	4,419,986,548

(b) Concept: ElectricPlantInServiceAdjustments

The adjustments column represents the January 1, 2024, transfer of our South Dakota plant balances to NorthWestern Energy Public Service Corporation as part of effectuating the holding company reorganization.

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

ELECTRIC PLANT LEASED TO OTHERS (Account 104)
Line No.	LesseeName Name of Lessee (a)	IndicationOfAssociatedCompany * (Designation of Associated Company) (b)	LeaseDescription Description of Property Leased (c)	CommissionAuthorization Commission Authorization (d)	ExpirationDateOfLease Expiration Date of Lease (e)	ElectricPlantLeasedToOthers Balance at End of Year (f)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47	TOTAL

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

ELECTRIC PLANT HELD FOR FUTURE USE (Account 105)
Report separately each property held for future use at end of the year having an original cost of $250,000 or more. Group other items of property held for future use. For property having an original cost of $250,000 or more previously used in utility operations, now held for future use, give in column (a), in addition to other required information, the date that utility use of such property was discontinued, and the date the original cost was transferred to Account 105.
Line No.	ElectricPlantHeldForFutureUseDescription Description and Location of Property (a)	ElectricPlantPropertyClassifiedAsHeldForFutureUseOriginalDate Date Originally Included in This Account (b)	ElectricPlantPropertyClassifiedAsHeldForFutureUseExpectedUseInServiceDate Date Expected to be used in Utility Service (c)	ElectricPlantHeldForFutureUse Balance at End of Year (d)
1	Land and Rights:
2	Townsend Transmission Sub site	01/01/2011	12/31/2027	1,763,378
3	Missoula Miller Creek Sub site	01/01/2001	03/31/2025	625,904
4	Billings Metra Sub Site	07/01/2019	12/31/2028	595,346
5	Minor Projects (Less than $250,000 - 17 items)			1,177,435
21	Other Property:
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47	TOTAL			4,162,063

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

CONSTRUCTION WORK IN PROGRESS - - ELECTRIC (Account 107)
Report below descriptions and balances at end of year of projects in process of construction (107). Show items relating to "research, development, and demonstration" projects last, under a caption Research, Development, and Demonstrating (see Account 107 of the Uniform System of Accounts). Minor projects (5% of the Balance End of the Year for Account 107 or $1,000,000, whichever is less) may be grouped.
Line No.	ConstructionWorkInProgressProjectDescription Description of Project (a)	ConstructionWorkInProgress Construction work in progress - Electric (Account 107) (b)
1	Description of Project (a)
2	Yellowstone Gen Station	16,777,011
3	Bozeman Division Electric Capital Blanket Growth	5,250,117
4	Hamilton North Sub	4,958,758
5	Hauser U1 Turb-Gen Upgrade	4,752,366
6	Holter U2 Turbine Upgrade	4,670,143
7	Holter U2 Generator Rewind	2,953,062
8	Great Falls Eastside-SE-Southside	2,601,262
9	Black Eagle Spillway Upgrade for Ice	2,552,716
10	Autotransformer Upgrade	2,515,528
11	CU4 Capital Items	2,502,137
12	ADMS Training Development	2,433,353
13	Bozeman WS Bank 1	2,294,138
14	Cenex CG and VS Replace	2,141,639
15	New Manhattan Sub	2,129,637
16	Miller Stevinsville A Line	2,032,306
17	Missoula Wildfire Hardening	1,692,641
18	500kV Broadview Cap Replace	1,592,014
19	Helena Wildfire Hardening	1,335,263
20	Clyde Pk Sb Rebuild	1,288,393
21	SBSQ Mill Creek	1,177,215
22	Minor Projects (Less than $1,000,000 - 285 items)	21,033,643
43	Total	88,683,342

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

ACCUMULATED PROVISION FOR DEPRECIATION OF ELECTRIC UTILITY PLANT (Account 108)
Explain in a footnote any important adjustments during year. Explain in a footnote any difference between the amount for book cost of plant retired, Line 12, column (c), and that reported for electric plant in service, page 204, column (d), excluding retirements of non-depreciable property. The provisions of Account 108 in the Uniform System of Accounts require that retirements of depreciable plant be recorded when such plant is removed from service. If the respondent has a significant amount of plant retired at year end which has not been recorded and/or classified to the various reserve functional classifications, make preliminary closing entries to tentatively functionalize the book cost of the plant retired. In addition, include all costs included in retirement work in progress at year end in the appropriate functional classifications. Show separately interest credits under a sinking fund or similar method of depreciation accounting.
Line No.	Item (a)	Total (c + d + e) (b)	Electric Plant in Service (c)	Electric Plant Held for Future Use (d)	Electric Plant Leased To Others (e)
Section A. Balances and Changes During Year
1	AccumulatedProvisionForDepreciationOfElectricUtilityPlant Balance Beginning of Year	(a) 1,990,020,890	1,990,020,890
2	Depreciation Provisions for Year, Charged to
3	DepreciationExpenseExcludingAdjustments (403) Depreciation Expense	121,132,871	121,132,871
4	DepreciationExpenseForAssetRetirementCosts (403.1) Depreciation Expense for Asset Retirement Costs
5	ExpensesOfElectricPlantLeasedToOthers (413) Exp. of Elec. Plt. Leas. to Others
6	TransportationExpensesClearing Transportation Expenses-Clearing
7	OtherClearingAccounts Other Clearing Accounts
8	OtherAccounts Other Accounts (Specify, details in footnote):
9.1	Transfer to NorthWestern Energy Public Service Corporation on January 1, 2024	383,578,812	383,578,812
10	DepreciationProvision TOTAL Deprec. Prov for Year (Enter Total of lines 3 thru 9)	262,445,941	262,445,941
11	Net Charges for Plant Retired:
12	BookCostOfRetiredPlant Book Cost of Plant Retired	45,318,017	45,318,017
13	CostOfRemovalOfPlant Cost of Removal	13,390,132	13,390,132
14	SalvageValueOfRetiredPlant Salvage (Credit)	2,190,857	2,190,857
15	NetChargesForRetiredPlant TOTAL Net Chrgs. for Plant Ret. (Enter Total of lines 12 thru 14)	56,517,292	56,517,292
16	OtherAdjustmentsToAccumulatedDepreciation Other Debit or Cr. Items (Describe, details in footnote):	2,682,070	2,682,070
17.1	Transfers	2,682,541	2,682,541
17.2	Other	467	467
18	BookCostOfAssetRetirementCosts Book Cost or Asset Retirement Costs Retired
19	AccumulatedProvisionForDepreciationOfElectricUtilityPlant Balance End of Year (Enter Totals of lines 1, 10, 15, 16, and 18)	1,673,739,727	1,673,739,727	0	0
Section B. Balances at End of Year According to Functional Classification
20	AccumulatedDepreciationSteamProduction Steam Production	39,780,913	39,780,913
21	AccumulatedDepreciationNuclearProduction Nuclear Production	0
22	AccumulatedDepreciationHydraulicProductionConventional Hydraulic Production-Conventional	138,627,959	138,627,959
23	AccumulatedDepreciationHydraulicProductionPumpedStorage Hydraulic Production-Pumped Storage	0
24	AccumulatedDepreciationOtherProduction Other Production	83,132,066	83,132,066
25	AccumulatedDepreciationTransmission Transmission	434,531,589	434,531,589
26	AccumulatedDepreciationDistribution Distribution	875,323,542	875,323,542
27	AccumulatedDepreciationRegionalTransmissionAndMarketOperation Regional Transmission and Market Operation	0
28	AccumulatedDepreciationGeneral General	102,343,658	102,343,658
29	AccumulatedProvisionForDepreciationOfElectricUtilityPlant TOTAL (Enter Total of lines 20 thru 28)	1,673,739,727	1,673,739,727	0	0

FOOTNOTE DATA

(a) Concept: AccumulatedProvisionForDepreciationOfElectricUtilityPlant

The beginning balance for Montana operations (pre-Holding Company formation) was $1,606,442,078.

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

INVESTMENTS IN SUBSIDIARY COMPANIES (Account 123.1)
Report below investments in Account 123.1, Investments in Subsidiary Companies. Provide a subheading for each company and list thereunder the information called for below. Sub-TOTAL by company and give a TOTAL in columns (e), (f), (g) and (h). (a) Investment in Securities - List and describe each security owned. For bonds give also principal amount, date of issue, maturity, and interest rate. (b) Investment Advances - Report separately the amounts of loans or investment advances which are subject to repayment, but which are not subject to current settlement. With respect to each advance show whether the advance is a note or open account. List each note giving date of issuance, maturity date, and specifying whether note is a renewal. Report separately the equity in undistributed subsidiary earnings since acquisition. The TOTAL in column (e) should equal the amount entered for Account 418.1. For any securities, notes, or accounts that were pledged designate such securities, notes, or accounts in a footnote, and state the name of pledgee and purpose of the pledge. If Commission approval was required for any advance made or security acquired, designate such fact in a footnote and give name of Commission, date of authorization, and case or docket number. Report column (f) interest and dividend revenues from investments, including such revenues from securities disposed of during the year. In column (h) report for each investment disposed of during the year, the gain or loss represented by the difference between cost of the investment (or the other amount at which carried in the books of account if different from cost) and the selling price thereof, not including interest adjustment includible in column (f). Report on Line 42, column (a) the TOTAL cost of Account 123.1.
Line No.	DescriptionOfInvestmentsInSubsidiaryCompanies Description of Investment (a)	DateOfAcquisitionInvestmentsInSubsidiaryCompanies Date Acquired (b)	DateOfMaturityInvestmentsInSubsidiaryCompanies Date of Maturity (c)	InvestmentInSubsidiaryCompanies Amount of Investment at Beginning of Year (d)	EquityInEarningsOfSubsidiaryCompanies Equity in Subsidiary Earnings of Year (e)	InterestAndDividendRevenueFromInvestments Revenues for Year (f)	InvestmentInSubsidiaryCompanies Amount of Investment at End of Year (g)	InvestmentGainLossOnDisplosal Gain or Loss from Investment Disposed of (h)
1	Canadian Montana Pipeline Corporation - Equity in Undistributed Earnings	02/15/2002		2,107,015	156,027		2,263,042
2	Canadian Montana Pipeline Corporation - Paid in Capital	02/15/2002		1,388,429			1,388,429
3	Canadian Montana Pipeline Corporation - Translation Adjustment	02/15/2002		1,686,317			1,682,015
4	Havre Pipeline Company - Equity in Undistributed Earnings	12/01/2013		3,464,170	1,599,990		5,064,160
5	Havre Pipeline Company - Paid in Capital	12/01/2013		16,626,690			16,626,690
6	NorthWestern Energy Public Service Corporation - Capital Stock	05/30/2024		1			0
7	NorthWestern Energy Solutions - Capital Stock	06/01/2018		11,852,827			0
8	NorthWestern Energy Solutions - Equity in Undistributed Earnings	06/01/2018		55,682			0
9	NorthWestern Services, LLC - Equity in Undistributed Earnings			331,987			0
10	NorthWestern Services, LLC - Paid in Capital			(a) 1,803,694			0
11	Risk Partners Assurance, Ltd. - Capital Stock			1,520,000			0
12	Risk Partners Assurance, Ltd. - Equity in Undistributed Earnings			422,834			0
13				2,135,681			0
14				1,097,166			0
15				5,181,761	156,027		5,333,486
16				13,162,520	1,599,990		11,562,530
17				11,797,145
18				1			0
42	Total Cost of Account 123.1 $		Total	33,374,273	1,443,963		16,896,016

FOOTNOTE DATA

(a) Concept: InvestmentInSubsidiaryCompanies

The table below is included to represent FERC Form 1 Page 224-225 in the appropriate format:

Line No.	Subsidiary Company [Axis]	Investments in Subsidiary Companies [Axis]	Description of Investment (a)	Date Acquired (b)	Date of Maturity (c)	Amount of Investment at Beginning of Year (d)	Equity in Subsidiary Earnings of Year (e)	Revenues for Year (f)	Amount of Investment at End of Year (g)	Gain or Loss from Investment Disposed of (h)
	Subsidiary Company [Axis]
1.1	NorthWestern Services, LLC	Paid-In-Capital [Member]	NorthWestern Services, LLC - Paid in Capital			1,803,694			0
1.2	NorthWestern Services, LLC	Unappropriated Undistributed Subsidiary Earnings [Member]	NorthWestern Services, LLC - Equity in Undistributed Earnings			331,987			0
1.3	NorthWestern Services, LLC	Total				2,135,681			0
1.4	Risk Partners Assurance, Ltd.	Captial Stock [Member]	Risk Partners Assurance, Ltd. - Capital Stock			1,520,000			0
1.5	Risk Partners Assurance, Ltd.	Unappropriated Undistributed Subsidiary Earnings [Member]	Risk Partners Assurance, Ltd. - Equity in Undistributed Earnings			-422,834			0
1.6	Risk Partners Assurance, Ltd.	Total				1,097,166			0
1.7	Canadian Montana Pipeline Corporation	Other Investments in Subsidiary Companies [Member]	Canadian Montana Pipeline Corporation - Translation Adjustment	2002-02-15		1,686,317			1,682,015
1.8	Canadian Montana Pipeline Corporation	Paid-In-Capital [Member]	Canadian Montana Pipeline Corporation - Paid in Capital	2002-02-15		1,388,429			1,388,429
1.9	Canadian Montana Pipeline Corporation	Unappropriated Undistributed Subsidiary Earnings [Member]	Canadian Montana Pipeline Corporation - Equity in Undistributed Earnings	2002-02-15		2,107,015	156,027		2,263,042
1.10	Canadian Montana Pipeline Corporation	Total				5,181,761	156,027		5,333,486
1.11	Havre Pipeline Company	Paid-In-Capital [Member]	Havre Pipeline Company - Paid in Capital	2013-12-01		16,626,690			16,626,690
1.12	Havre Pipeline Company	Unappropriated Undistributed Subsidiary Earnings [Member]	Havre Pipeline Company - Equity in Undistributed Earnings	2013-12-01		-3,464,170	1,599,990		-5,064,160
1.13	Havre Pipeline Company	Total				13,162,520	1,599,990		11,562,530
1.14	NorthWestern Energy Solutions	Captial Stock [Member]	NorthWestern Energy Solutions - Capital Stock	2018-06-01		11,852,827			0
1.15	NorthWestern Energy Solutions	Unappropriated Undistributed Subsidiary Earnings [Member]	NorthWestern Energy Solutions - Equity in Undistributed Earnings	2018-06-01		-55,682			0
1.16	NorthWestern Energy Solutions	Total				11,797,145
1.17	NorthWestern Energy Public Service Corporation	Captial Stock [Member]	NorthWestern Energy Public Service Corporation - Capital Stock	2024-05-30		1			0
1.18	NorthWestern Energy Public Service Corporation	Total				1			0
1.19						33,374,273	1,443,963		16,896,016

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

MATERIALS AND SUPPLIES
For Account 154, report the amount of plant materials and operating supplies under the primary functional classifications as indicated in column (a); estimates of amounts by function are acceptable. In column (d), designate the department or departments which use the class of material. Give an explanation of important inventory adjustments during the year (in a footnote) showing general classes of material and supplies and the various accounts (operating expenses, clearing accounts, plant, etc.) affected debited or credited. Show separately debit or credits to stores expense clearing, if applicable.
Line No.	Account (a)	Balance Beginning of Year (b)	Balance End of Year (c)	Department or Departments which Use Material (d)
1	Fuel Stock (Account 151)	9,710,818	2,248,613	Electric & Gas
2	Fuel Stock Expenses Undistributed (Account 152)
3	Residuals and Extracted Products (Account 153)
4	Plant Materials and Operating Supplies (Account 154)
5	Assigned to - Construction (Estimated)	80,236,296	76,163,131	Electric, Gas, & Common
6	Assigned to - Operations and Maintenance
7	Production Plant (Estimated)
8	Transmission Plant (Estimated)	804,673	405,337	Electric & Gas
9	Distribution Plant (Estimated)	1,269,432	773,116	Electric, Gas, & Common
10	Regional Transmission and Market Operation Plant (Estimated)	2,944,092	2,439,130	Electric, Gas, & Common
11	Assigned to - Other (provide details in footnote)
12	TOTAL Account 154 (Enter Total of lines 5 thru 11)	85,254,493	79,780,714
13	Merchandise (Account 155)
14	Other Materials and Supplies (Account 156)
15	Nuclear Materials Held for Sale (Account 157) (Not applic to Gas Util)
16	Stores Expense Undistributed (Account 163)
17
18
19
20	TOTAL Materials and Supplies	94,965,311	(a)(b) 82,029,327

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

FOOTNOTE DATA

(a) Concept: MaterialsAndOperatingSupplies

Line No.	Account (a)	Gas (b)	Electric Transmission (c)	Other Electric (d)	Total (e)
1	Fuel Stock (Account 151)	773,056	-	1,475,557	2,248,613
2	Fuel Stock Expense Undistributed (Account 152)				-
3	Residuals and Extracted Products (Account 153)
4	Plant Materials and Operating Supplies (Account 154)
5	Assigned to - Construction (Estimated)	11,904,166.00	12,268,342.00	51,990,623.00	76,163,131
6	Assigned to - Operatons and Maintenance
7	Production Plant (Estimated)	3,070	-	402,267	405,337
8	Transmission Plant (Estimated)	190,396	582,720.00	-	773,116
9	Distribution Plant (Estimated)	371,956	-	2,067,174	2,439,130
10	Regional Transmission and Market Operation Plant (Estimated)
11	Assigned to - Other
12	TOTAL Account 154 (Enter Total of lines 5 thru 10)	12,469,588	12,851,062	54,460,064	79,780,714
13	Merchandise (Account 155)
14	Other Materials and Supplies (Account 156)
15	Nuclear Materials Held for Sale (Account 157)
16	Store Expense Undistributed (Account 163)
17
18
19
20	TOTAL Materials and Supplies (Per Balance Sheet)	13,242,644	12,851,062	55,935,621	82,029,327

(b) Concept: MaterialsAndOperatingSupplies

Line No.	Account (a)	Balance Beginning of Year (b)	Balance End of Year (c )	Estimate of Portion Attributable to Construction	Balance End of Year w/ Assigned to Construction (c )	Deparment or Departments which Use Material (d)
1	Fuel Stock (Account 151)	2,155,210	2,248,613		2,248,613	Electric & Gas
2	Fuel Stock Expense Undistributed (Account 152)
3	Residuals and Extracted Products (Account 153)
4	Plant Materials and Operating Supplies (Account 154)
5	Assigned to - Construction (Estimated)	-	-	76,163,131	76,163,131	Electric, Gas, & Common
6	Assigned to - Operatons and Maintenance
7	Production Plant (Estimated)	8,316,399	8,939,134	(8,533,796)	405,337	Electric & Gas
8	Transmission Plant (Estimated)	17,126,102	17,049,982	(16,276,867)	773,116	Electric, Gas, & Common
9	Distribution Plant (Estimated)	40,356,652	53,791,598	(51,352,468)	2,439,130	Electric, Gas, & Common
10	Regional Transmission and Market Operation Plant (Estimated)				-
11	Assigned to - Other	-	-		-
12	TOTAL Account 154 (Enter Total of lines 5 thru 10)	65,799,153	79,780,714	-	79,780,714
13	Merchandise (Account 155)
14	Other Materials and Supplies (Account 156)
15	Nuclear Materials Held for Sale (Account 157)
16	Store Expense Undistributed (Account 163)
17
18
19
20	TOTAL Materials and Supplies (Per Balance Sheet)	67,954,363	82,029,327	-	82,029,327

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

Allowances (Accounts 158.1 and 158.2)
Report below the particulars (details) called for concerning allowances. Report all acquisitions of allowances at cost. Report allowances in accordance with a weighted average cost allocation method and other accounting as prescribed by General Instruction No. 21 in the Uniform System of Accounts. Report the allowances transactions by the period they are first eligible for use: the current year’s allowances in columns (b)-(c), allowances for the three succeeding years in columns (d)-(i), starting with the following year, and allowances for the remaining succeeding years in columns (j)-(k). Report on Line 4 the Environmental Protection Agency (EPA) issued allowances. Report withheld portions Lines 36-40. Report on Line 5 allowances returned by the EPA. Report on Line 39 the EPA’s sales of the withheld allowances. Report on Lines 43-46 the net sales proceeds and gains/losses resulting from the EPA’s sale or auction of the withheld allowances. Report on Lines 8-14 the names of vendors/transferors of allowances acquired and identify associated companies (See "associated company" under "Definitions" in the Uniform System of Accounts). Report on Lines 22 - 27 the name of purchasers/ transferees of allowances disposed of and identify associated companies. Report the net costs and benefits of hedging transactions on a separate line under purchases/transfers and sales/transfers. Report on Lines 32-35 and 43-46 the net sales proceeds and gains or losses from allowance sales.
		Current Year		Year One		Year Two		Year Three		Future Years		Totals
Line No.	SO2 Allowances Inventory (Account 158.1) (a)	No. (b)	Amt. (c)	No. (d)	Amt. (e)	No. (f)	Amt. (g)	No. (h)	Amt. (i)	No. (j)	Amt. (k)	No. (l)	Amt. (m)
1	Balance-Beginning of Year	4,106		4,106		4,106		4,105		37,412		53,835
2
3	Acquired During Year:
4	Issued (Less Withheld Allow)
5	Returned by EPA
6
7
8
9
10
11
12
13
14
15	Total
16
17	Relinquished During Year:
18	Charges to Account 509
19	Other:
20	Allowances Used
21	Cost of Sales/Transfers:
22
23
24
25
26
27
28	Total
29	Balance-End of Year	4,106		4,106		4,106		4,105		37,412		53,835
30
31	Sales:
32	Net Sales Proceeds(Assoc. Co.)
33	Net Sales Proceeds (Other)
34	Gains
35	Losses
	Allowances Withheld (Acct 158.2)
36	Balance-Beginning of Year
37	Add: Withheld by EPA
38	Deduct: Returned by EPA
39	Cost of Sales
40	Balance-End of Year
41
42	Sales
43	Net Sales Proceeds (Assoc. Co.)
44	Net Sales Proceeds (Other)
45	Gains
46	Losses

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

Allowances (Accounts 158.1 and 158.2)
Report below the particulars (details) called for concerning allowances. Report all acquisitions of allowances at cost. Report allowances in accordance with a weighted average cost allocation method and other accounting as prescribed by General Instruction No. 21 in the Uniform System of Accounts. Report the allowances transactions by the period they are first eligible for use: the current year’s allowances in columns (b)-(c), allowances for the three succeeding years in columns (d)-(i), starting with the following year, and allowances for the remaining succeeding years in columns (j)-(k). Report on Line 4 the Environmental Protection Agency (EPA) issued allowances. Report withheld portions Lines 36-40. Report on Line 5 allowances returned by the EPA. Report on Line 39 the EPA’s sales of the withheld allowances. Report on Lines 43-46 the net sales proceeds and gains/losses resulting from the EPA’s sale or auction of the withheld allowances. Report on Lines 8-14 the names of vendors/transferors of allowances acquired and identify associated companies (See "associated company" under "Definitions" in the Uniform System of Accounts). Report on Lines 22 - 27 the name of purchasers/ transferees of allowances disposed of and identify associated companies. Report the net costs and benefits of hedging transactions on a separate line under purchases/transfers and sales/transfers. Report on Lines 32-35 and 43-46 the net sales proceeds and gains or losses from allowance sales.
		Current Year		Year One		Year Two		Year Three		Future Years		Totals
Line No.	NOx Allowances Inventory (Account 158.1) (a)	No. (b)	Amt. (c)	No. (d)	Amt. (e)	No. (f)	Amt. (g)	No. (h)	Amt. (i)	No. (j)	Amt. (k)	No. (l)	Amt. (m)
1	Balance-Beginning of Year
2
3	Acquired During Year:
4	Issued (Less Withheld Allow)
5	Returned by EPA
6
7
8
9
10
11
12
13
14
15	Total
16
17	Relinquished During Year:
18	Charges to Account 509
19	Other:
20	Allowances Used
21	Cost of Sales/Transfers:
22
23
24
25
26
27
28	Total
29	Balance-End of Year
30
31	Sales:
32	Net Sales Proceeds(Assoc. Co.)
33	Net Sales Proceeds (Other)
34	Gains
35	Losses
	Allowances Withheld (Acct 158.2)
36	Balance-Beginning of Year
37	Add: Withheld by EPA
38	Deduct: Returned by EPA
39	Cost of Sales
40	Balance-End of Year
41
42	Sales
43	Net Sales Proceeds (Assoc. Co.)
44	Net Sales Proceeds (Other)
45	Gains
46	Losses

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

EXTRAORDINARY PROPERTY LOSSES (Account 182.1)
				WRITTEN OFF DURING YEAR
Line No.	DescriptionOfExtraordinaryPropertyLoss Description of Extraordinary Loss [Include in the description the date of Commission Authorization to use Acc 182.1 and period of amortization (mo, yr to mo, yr).] (a)	ExtraordinaryPropertyLossesNotYetRecognized Total Amount of Loss (b)	ExtraordinaryPropertyLossesRecognized Losses Recognized During Year (c)	ExtraordinaryPropertyLossesWrittenOffAccountCharged Account Charged (d)	ExtraordinaryPropertyLossesWrittenOff Amount (e)	ExtraordinaryPropertyLosses Balance at End of Year (f)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
20	TOTAL

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

UNRECOVERED PLANT AND REGULATORY STUDY COSTS (182.2)
				WRITTEN OFF DURING YEAR
Line No.	DescriptionOfUnrecoveredPlantAndRegulatoryStudyCosts Description of Unrecovered Plant and Regulatory Study Costs [Include in the description of costs, the date of COmmission Authorization to use Acc 182.2 and period of amortization (mo, yr to mo, yr)] (a)	UnrecoveredPlantAndRegulatoryStudyCostsNotYetRecognized Total Amount of Charges (b)	UnrecoveredPlantAndRegulatoryStudyCostsRecognized Costs Recognized During Year (c)	UnrecoveredPlantAndRegulatoryStudyCostsWrittenOffAccountCharged Account Charged (d)	UnrecoveredPlantAndRegulatoryStudyCostsWrittenOff Amount (e)	UnrecoveredPlantAndRegulatoryStudyCosts Balance at End of Year (f)
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49	TOTAL

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

Transmission Service and Generation Interconnection Study Costs
Report the particulars (details) called for concerning the costs incurred and the reimbursements received for performing transmission service and generator interconnection studies. List each study separately. In column (a) provide the name of the study. In column (b) report the cost incurred to perform the study at the end of period. In column (c) report the account charged with the cost of the study. In column (d) report the amounts received for reimbursement of the study costs at end of period. In column (e) report the account credited with the reimbursement received for performing the study.
Line No.	DescriptionOfStudyPerformed Description (a)	StudyCostsIncurred Costs Incurred During Period (b)	StudyCostsAccountCharged Account Charged (c)	StudyCostsReimbursements Reimbursements Received During the Period (d)	StudyCostsAccountReimbursed Account Credited With Reimbursement (e)
1	Transmission Studies
2	FAC Studies	8,647	253		253
3	SIS Studies	205,940	253	444,554	253
4	Line Interconnection Studies	77,062	253		253
20	Total	291,649		444,554
21	Generation Studies
22	FAC Studies	275,772	253	152,033	253
23	SIS Studies	43,292	253	200,000	253
24	FEA Studies	95,926	253	90,815	253
25	Optional Studies	12,599	253	30,000	253
39	Total	427,589		472,848
40	Grand Total	719,238		917,402

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

OTHER REGULATORY ASSETS (Account 182.3)
Report below the particulars (details) called for concerning other regulatory assets, including rate order docket number, if applicable. Minor items (5% of the Balance in Account 182.3 at end of period, or amounts less than $100,000 which ever is less), may be grouped by classes. For Regulatory Assets being amortized, show period of amortization.
				CREDITS
Line No.	DescriptionAndPurposeOfOtherRegulatoryAssets Description and Purpose of Other Regulatory Assets (a)	OtherRegulatoryAssets Balance at Beginning of Current Quarter/Year (b)	IncreaseDecreaseInOtherRegulatoryAssets Debits (c)	OtherRegulatoryAssetsWrittenOffAccountCharged Written off During Quarter/Year Account Charged (d)	OtherRegulatoryAssetsWrittenOffRecovered Written off During the Period Amount (e)	OtherRegulatoryAssets Balance at end of Current Quarter/Year (f)
1	Flow-through Income Taxes (Montana)	483,949,425	39,889,047	Various	1,823,305	522,015,167
2	Excess Deferred Income Taxes (Montana)	44,656,588	37,333	410.1	5,653,523	(b) 39,040,398
3	Basin Creek Capital Lease (Montana)	3,772,893	0	243	1,327,129	2,445,764
4	BPA Residential Exchange Program (Montana) - Docket 2018.8.49 Order 7630; Annual Amortization	1,171,046	3,261,838	254	3,288,943	1,143,941
5	Property Tax Tracker (Montana) - Docket 2017.11.86 - Order 7580a; Annual Amortization	0	43,174,016	(2)407	36,807,463	6,366,553
6	FAS 106 (Montana) - Docket 93.6.24 and Docket 2009.9.129	6,855,119	369,072	(2)926	4,250,808	2,973,383
7	FAS 112 (Montana) - Docket 93.6.24 and Docket 2009.9.129	3,687,034	0	(2)926	759,659	2,927,375
8	Compensated Absences (Montana) - Docket 97.11.219	11,383,690	1,455,006	242	862,182	11,976,514
9	Pension Plan - MT	73,823,616			17,104,283	56,719,333
10	Montana Consumer Counsel Tax (Montana) - Docket 2018.10.67 - Order 7637	0	73,261	Various	42,443	30,818
11	Montana Public Service Commission (Montana) - Docket 2017.9.78 - Order 7568	2,732,805	814,556		1,081,833	2,465,528
12	Montana Wildfire Mitigation	1,623,113	15,744,426		0	17,367,539
13	Asset Retirement Obligation (Montana)	17,807,072	1,879,578		8,289,599	11,397,051
14	South Dakota:					0
15	Flow-through Income Taxes (South Dakota)	69,502,155			(a) 69,502,155	0
16	Excess Deferred Income Taxes (South Dakota)	6,747,525			6,747,525	0
17	Pension Plan (South Dakota)	5,814,695			5,814,695	0
18	Manufactured Gas Plants (South Dakota) - Docket NG 11-003	11,130,554			11,130,554	0
19	Rate Case Costs (South Dakota) Docket EL 23-016	190,623			190,623	0
20	Field Inventory (South Dakota)	172,275			172,275	0
21	Asset Retirement Obligation (South Dakota)	1,005,325			1,005,325	0
44	TOTAL	746,025,553	106,698,133		175,854,322	676,869,364

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

FOOTNOTE DATA

(a) Concept: OtherRegulatoryAssetsWrittenOffRecovered

On January 1, 2024, NorthWestern Corporation contributed the assets and liabilities of its South Dakota and Nebraska regulated utilities to NorthWestern Energy Public Service Corporation, resulting in NorthWestern Corporation owning and operating the Montana regulated utility and NorthWestern Energy Public Service Corporation owning and operating the Nebraska and South Dakota utilities. The folowing balances represent the regulatory assets contributed to NorthWestern Energy Public Service Corporation on Jaunary 1, 2024.

Description	Balance Contributed
Flow-through Income Taxes (South Dakota)	69,502,155
Excess Deferred Income Taxes (South Dakota)	6,747,525
Pension Plan (South Dakota)	5,814,695
Manufactured Gas Plants (South Dakota) - Docket NG 11-003	11,130,554
Rate Case Costs (South Dakota) Docket EL 23-016	190,623
Field Inventory (South Dakota)	172,275
Asset Retirement Obligation (South Dakota)	1,005,325
Total	94,563,152

(b) Concept: OtherRegulatoryAssets

Line No.	Description (a)	(b)	(c)	(d)

	MONTANA:
		12/31/2023
		Protected	Unprotected
	TCJA Excess ADIT Account Reduced	190	190	Subtotal
	Reg Asset Acccount Impacted	182.3	182.3	182.3
1	Electric:
2	Regulatory Assets / Liabilities		15,684	15,684
3	Unbilled Revenue		137,446	137,446
4	Compensation Accruals		150,277	150,277
5	Reserves & Accruals		35,988	35,988
6	Intangible amortization		-	-
7	Pension / Postretirement Benefits		985,547	985,547
8	Environmental Liability		52,894	52,894
9	Interest Rate Hedge		-	-
10	Customer Advances		465,978	465,978
11	Excess Tax Depreciation / Other Property			-
12	Net Operating Loss	25,096,836	-	25,096,836
13	Total Electric	25,096,836	1,843,814	26,940,650
14	Gas:
15	Regulatory Assets / Liabilities		(23,077)	(23,077)
16	Unbilled Revenue		481,062	481,062
17	Compensation Accruals		525,970	525,970
18	Reserves & Accruals		104,575	104,575
19	Intangible amortization		-	-
20	Pension / Postretirement Benefits		3,450,731	3,450,731
21	Environmental Liability		185,129	185,129
22	Interest Rate Hedge		-	-
23	Customer Advances		1,137,656	1,137,656
24	Excess Tax Depreciation / Other Property			-
25	Net Operating Loss	-	-	-
26	Total Gas	-	5,862,046	5,862,046
27	Other (Specify)	-	94,696	94,696
28	Subtotal	25,096,836	7,800,556	32,897,392
29	Gross-up	8,970,882	2,788,315	11,759,197
30	Total	34,067,718	10,588,871	44,656,589
31
32	Other (Specify)
33	QF Obligations	-	-	-
34	NOL Carryforward	-	-	-
35	AMT Credit Carryforward	-	-	-
36	Production Tax Credit	-	-	-
37	Regulatory Assets / Liabilities	-	-	-
38	Other, net	-	94,696	94,696
39	Total	-	94,696	94,696
40
41
42		12/31/2024
43		Protected	Unprotected
44	TCJA Excess ADIT Account Reduced	190	190	Subtotal
45	Reg Asset Acccount Impacted	182.3	182.3	182.3
46	Electric:
47	Regulatory Assets / Liabilities		-	-
48	Unbilled Revenue		-	-
49	Compensation Accruals		-	-
50	Reserves & Accruals		-	-
51	Intangible amortization		-	-
52	Pension / Postretirement Benefits		-	-
53	Environmental Liability		-	-
54	Interest Rate Hedge		-	-
55	Customer Advances		-	-
56	Excess Tax Depreciation / Other Property			-
57	Net Operating Loss	24,175,218	-	24,175,218
58	Total Electric	24,175,218	-	24,175,218
59	Gas:
60	Regulatory Assets / Liabilities		(17,949)	(17,949)
61	Unbilled Revenue		374,160	374,160
62	Compensation Accruals		409,088	409,088
63	Reserves & Accruals		81,336	81,336
64	Intangible amortization		-	-
65	Pension / Postretirement Benefits		2,683,902	2,683,902
66	Environmental Liability		143,989	143,989
67	Interest Rate Hedge		-	-
68	Customer Advances		884,843	884,843
69	Excess Tax Depreciation / Other Property			-
70	Net Operating Loss	-	-	-
71	Total Gas	-	4,559,369	4,559,369
72	Other (Specify)	-	25,499	25,499
73	Subtotal	24,175,218	4,584,868	28,760,086
74	Gross-up	8,641,449	1,638,864	10,280,313
75	Total	32,816,667	6,223,732	39,040,399
76
77	Other (Specify)
78	QF Obligations	-	-	-
79	NOL Carryforward	-	-	-
80	AMT Credit Carryforward	-	-	-
81	Production Tax Credit	-	-	-
82	Regulatory Assets / Liabilities	-	-	-
83	Other, net	-	25,499	25,499
84	Total	-	25,499	25,499
85
86

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

MISCELLANEOUS DEFFERED DEBITS (Account 186)
Report below the particulars (details) called for concerning miscellaneous deferred debits. For any deferred debit being amortized, show period of amortization in column (a) Minor item (1% of the Balance at End of Year for Account 186 or amounts less than $100,000, whichever is less) may be grouped by classes.
				CREDITS
Line No.	Description of Miscellaneous Deferred Debits (a)	Balance at Beginning of Year (b)	Debits (c)	Credits Account Charged (d)	Credits Amount (e)	Balance at End of Year (f)
1	Montana Operations:
2	Energy Stored in Out of State Utilities (Montana)	0	11,649	555	11,605	44
3	500 kV Operations - Partner's Share (Montana)	149,231	0	131	0	149,231
4	PPLM Share of WET Tax (Montana)	3,034	25,289	131	26,437	1,886
5	Unamortized Debt Expense (Montana)	1,475,328	3,500	930.2	401,048	1,077,780
6	Transmission Line Rights (Montana)	45,464	0	116	45,464	0
7	South Dakota Operations:
8	Deferred Fuel for Electric Generation (South Dakota)	262,625		547	(a) 262,625	0
9	Unamortized Debt Expense (South Dakota)	372,312		930.2	372,312	0
10	Pension Requirement (South Dakota)	9,075,113		253	9,075,113	0
47	Miscellaneous Work in Progress
48	Deferred Regulatory Comm. Expenses (See pages 350 - 351)
49	TOTAL	11,084,645				930,479

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

FOOTNOTE DATA

(a) Concept: DecreaseInMiscellaneousDeferredExpense

On January 1, 2024, the South Dakota Operations miscellaneous deferred debit balances were distributed to NorthWestern Energy Public Service Corporation.

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

ACCUMULATED DEFERRED INCOME TAXES (Account 190)
Report the information called for below concerning the respondent’s accounting for deferred income taxes. At Other (Specify), include deferrals relating to other income and deductions.
Line No.	DescriptionOfAccumulatedDeferredIncomeTax Description and Location (a)	AccumulatedDeferredIncomeTaxes Balance at Beginning of Year (b)	AccumulatedDeferredIncomeTaxes Balance at End of Year (c)
1	Electric
2	Regulatory Asset/Liability	(a) 513,901	456,122
3	Unbilled Revenue	7,196,441	2,210,303
4	Compensation Accruals	7,832,297	7,112,215
5	Reserves & Accruals	3,114,841	1,894,237
6	Pension / Postretirement Benefits	11,049,340	7,405,206
7	Other	(b) 105,938,033	90,728,182
8	TOTAL Electric (Enter Total of lines 2 thru 7)	135,644,853	109,806,265
9	Gas
10	Regulatory Asset/Liability	227,902	177,787
11	Unbilled Revenue	3,407,247	915,938
12	Compensation Accruals	2,884,161	2,744,498
13	Reserves & Accruals	421,788	169,263
14	Pension / Postretirement Benefits	4,082,073	2,963,577
15	Other	(c) 42,014,497	36,819,931
16	TOTAL Gas (Enter Total of lines 10 thru 15)	53,037,668	43,790,994
17	Other (Specify)	(d) 101,200,493	40,416,632
18	TOTAL (Acct 190) (Total of lines 8, 16 and 17)	289,883,014	194,013,891

Notes

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

FOOTNOTE DATA

(a) Concept: AccumulatedDeferredIncomeTaxes

	MONTANA OPERATIONS	SOUTH DAKOTA
Accumulated Deferred Income Taxes (Account 190)
Description and Location	Balance at Beginning of Year	Balance at Beginning of Year
(a)	(d)	(f)
Electric
Regulatory Asset/Liability	513,901	-
Unbilled Revenue	5,200,338	1,996,104
Compensation Accruals	5,989,387	814,287
Reserves & Accruals	2,726,983	387,858
Pension / Postretirement Benefits	11,773,163	(723,823)
Environmental Liability	1,598,768	2,087,963
Interest Rate Hedge	3,366,964	(50,170)
Customer Advances	22,253,438	-
NOL Carryforward	56,571,417	20,109,652
Total Electric	109,994,359	24,621,871
Gas
Regulatory Asset/Liability	199,629	28,272
Unbilled Revenue	2,021,842	1,385,405
Compensation Accruals	2,329,206	554,955
Reserves & Accruals	152,202	269,586
Pension / Postretirement Benefits	4,579,123	(497,050)
Environmental Liability	623,259	1,450,041
Interest Rate Hedge	-	(36,330)
Customer Advances	6,046,233	-
NOL Carryforward	25,726,954	8,204,341
Total Gas	41,678,448	11,359,220
Other (Specify)	38,406,930	62,515,525
Total (Acct 190)	190,079,737	98,496,616

(b) Concept: AccumulatedDeferredIncomeTaxes

	Balance at Beginning of Year	Balance at End of Year
	(b)	( c)
Environmental Liability	3,686,732	1,532,474
Interest Rate Hedge	3,316,794	3,205,349
Customer Advances	22,253,438	25,596,315
NOL Carryforward	76,681,069	60,394,044
	105,938,033	90,728,182

	Balance at Beginning of Year	Balance at End of Year
	(b)	( c)
Environmental Liability	2,073,299	598,740
Interest Rate Hedge	(36,330)	-
Customer Advances	6,046,233	6,858,243
NOL Carryforward	33,931,295	29,362,948
	42,014,497	36,819,931

(d) Concept: AccumulatedDeferredIncomeTaxes

Account 190 Other (Specify)	Balance at Beginning of Year	Balance at End of Year
NOL Carryforward	2,698,127	59,264
Production Tax Credit	94,283,080	35,601,979
Other, net	4,219,286	4,755,389
Total	101,200,493	40,416,632

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

CAPITAL STOCKS (Account 201 and 204)
Report below the particulars (details) called for concerning common and preferred stock at end of year, distinguishing separate series of any general class. Show separate totals for common and preferred stock. If information to meet the stock exchange reporting requirement outlined in column (a) is available from the SEC 10-K Report Form filing, a specific reference to report form (i.e., year and company title) may be reported in column (a) provided the fiscal years for both the 10-K report and this report are compatible. Entries in column (b) should represent the number of shares authorized by the articles of incorporation as amended to end of year. Give details concerning shares of any class and series of stock authorized to be issued by a regulatory commission which have not yet been issued. The identification of each class of preferred stock should show the dividend rate and whether the dividends are cumulative or noncumulative. State in a footnote if any capital stock that has been nominally issued is nominally outstanding at end of year. Give particulars (details) in column (a) of any nominally issued capital stock, reacquired stock, or stock in sinking and other funds which is pledged, stating name of pledgee and purpose of pledge.
Line No.	Class and Series of Stock and Name of Stock Series (a)	Number of Shares Authorized by Charter (b)	Par or Stated Value per Share (c)	Call Price at End of Year (d)	Outstanding per Bal. Sheet (Total amount outstanding without reduction for amounts held by respondent) Shares (e)	Outstanding per Bal. Sheet (Total amount outstanding without reduction for amounts held by respondent) Amount (f)	Held by Respondent As Reacquired Stock (Acct 217) Shares (g)	Held by Respondent As Reacquired Stock (Acct 217) Cost (h)	Held by Respondent In Sinking and Other Funds Shares (i)	Held by Respondent In Sinking and Other Funds Amount (j)
1	Common Stock (Account 201)
2	Common Stock	200,000,000	0.01		100	1	0
9	Total	200,000,000			100	1
10	Preferred Stock (Account 204)
11	Preferred Stock - None Issued	50,000,000	0.01		0	0
17	Total	50,000,000			0	0

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

2024-12-31

Year/Period of Report

End of:

2024

Other Paid-in Capital
1. Report below the balance at the end of the year and the information specified below for the respective other paid-in capital accounts. Provide a subheading for each account and show a total for the account, as well as a total of all accounts for reconciliation with the balance sheet, page 112. Explain changes made in any account during the year and give the accounting entries effecting such change. Donations Received from Stockholders (Account 208) - State amount and briefly explain the origin and purpose of each donation. Reduction in Par or Stated Value of Capital Stock (Account 209) - State amount and briefly explain the capital changes that gave rise to amounts reported under this caption including identification with the class and series of stock to which related. Gain or Resale or Cancellation of Reacquired Capital Stock (Account 210) - Report balance at beginning of year, credits, debits, and balance at end of year with a designation of the nature of each credit and debit identified by the class and series of stock to which related. Miscellaneous Paid-In Capital (Account 211) - Classify amounts included in this account according to captions that, together with brief explanations, disclose the general nature of the transactions that gave rise to the reported amounts.
Line No.	Item (a)	Amount (b)
1	DonationsReceivedFromStockholdersAbstract Donations Received from Stockholders (Account 208)
2	DonationsReceivedFromStockholders Beginning Balance Amount
3	IncreasesDecreasesFromSalesOfDonationsReceivedFromStockholders Increases (Decreases) from Sales of Donations Received from Stockholders
4	DonationsReceivedFromStockholders Ending Balance Amount
5	ReductionInParOrStatedValueOfCapitalStockAbstract Reduction in Par or Stated Value of Capital Stock (Account 209)
6	ReductionInParOrStatedValueOfCapitalStock Beginning Balance Amount
7	IncreasesDecreasesDueToReductionsInParOrStatedValueOfCapitalStock Increases (Decreases) Due to Reductions in Par or Stated Value of Capital Stock
8	ReductionInParOrStatedValueOfCapitalStock Ending Balance Amount
9	GainOrResaleOrCancellationOfReacquiredCapitalStockAbstract Gain or Resale or Cancellation of Reacquired Capital Stock (Account 210)
10	GainOnResaleOrCancellationOfReacquiredCapitalStock Beginning Balance Amount
11	IncreasesDecreasesFromGainOrResaleOrCancellationOfReacquiredCapitalStock Increases (Decreases) from Gain or Resale or Cancellation of Reacquired Capital Stock
12	GainOnResaleOrCancellationOfReacquiredCapitalStock Ending Balance Amount
13	MiscellaneousPaidInCapitalAbstract Miscellaneous Paid-In Capital (Account 211)
14	MiscellaneousPaidInCapital Beginning Balance Amount	1,981,122,791
15.1	IncreasesDecreasesDueToMiscellaneousPaidInCapital Equity contribution from NorthWestern Energy Group, Inc.	60,000,000
15.2	IncreasesDecreasesDueToMiscellaneousPaidInCapital Stock Compensation	3,876,902
15	IncreasesDecreasesDueToMiscellaneousPaidInCapital Increases (Decreases) Due to Miscellaneous Paid-In Capital	63,876,902
16	MiscellaneousPaidInCapital Ending Balance Amount	2,044,999,693
17	OtherPaidInCapitalAbstract Other Paid in Capital
18	OtherPaidInCapitalDetail Beginning Balance Amount
19	IncreasesDecreasesInOtherPaidInCapital Increases (Decreases) in Other Paid-In Capital
20	OtherPaidInCapitalDetail Ending Balance Amount
40	OtherPaidInCapital Total	2,044,999,693

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

CAPITAL STOCK EXPENSE (Account 214)
Report the balance at end of the year of discount on capital stock for each class and series of capital stock. If any change occurred during the year in the balance in respect to any class or series of stock, attach a statement giving particulars (details) of the change. State the reason for any charge-off of capital stock expense and specify the account charged.
Line No.	NameOfClassAndSeriesOfStock Class and Series of Stock (a)	CapitalStockExpense Balance at End of Year (b)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22	TOTAL

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

LONG-TERM DEBT (Account 221, 222, 223 and 224)
Report by Balance Sheet Account the details concerning long-term debt included in Accounts 221, Bonds, 222, Reacquired Bonds, 223, Advances from Associated Companies, and 224, Other Long-Term Debt. For bonds assumed by the respondent, include in column (a) the name of the issuing company as well as a description of the bonds, and in column (b) include the related account number. For Advances from Associated Companies, report separately advances on notes and advances on open accounts. Designate demand notes as such. Include in column (a) names of associated companies from which advances were received, and in column (b) include the related account number. For receivers' certificates, show in column (a) the name of the court and date of court order under which such certificates were issued, and in column (b) include the related account number. In a supplemental statement, give explanatory details for Accounts 223 and 224 of net changes during the year. With respect to long-term advances, show for each company: (a)principal advanced during year (b) interest added to principal amount, and (c) principal repaid during year. Give Commission authorization numbers and dates. If the respondent has pledged any of its long-term debt securities, give particulars (details) in a footnote, including name of the pledgee and purpose of the pledge. If the respondent has any long-term securities that have been nominally issued and are nominally outstanding at end of year, describe such securities in a footnote. If interest expense was incurred during the year on any obligations retired or reacquired before end of year, include such interest expense in column (m). Explain in a footnote any difference between the total of column (m) and the total Account 427, Interest on Long-Term Debt and Account 430, Interest on Debt to Associated Companies. Give details concerning any long-term debt authorized by a regulatory commission but not yet issued.
Line No.	ClassAndSeriesOfObligationCouponRateDescription Class and Series of Obligation, Coupon Rate (For new issue, give commission Authorization numbers and dates) (a)	RelatedAccountNumber Related Account Number (b)	Principal Amount of Debt Issued (c)	LongTermDebtIssuanceExpensePremiumOrDiscount Total Expense, Premium or Discount (d)	LongTermDebtIssuanceExpenses Total Expense (e)	LongTermDebtPremium Total Premium (f)	LongTermDebtDiscount Total Discount (g)	NominalDateOfIssue Nominal Date of Issue (h)	DateOfMaturity Date of Maturity (i)	AmortizationPeriodStartDate AMORTIZATION PERIOD Date From (j)	AmortizationPeriodEndDate AMORTIZATION PERIOD Date To (k)	Outstanding (Total amount outstanding without reduction for amounts held by respondent) (l)	Interest for Year Amount (m)
1	Bonds (Account 221)
2	First Mortgage Bonds 5.71% (Montana)		(a) 55,000,000		549,881			10/15/2009	10/15/2039	10/15/2009	10/15/2039	55,000,000	3,140,500
3	First Mortgage Bonds 5.010% (Montana)		161,000,000		909,702	4,730,180		05/27/2010	05/01/2025	05/27/2010	05/01/2025	161,000,000	8,066,100
4	First Mortgage Bonds 4.15% (Montana)		60,000,000		376,671			08/10/2012	08/10/2042	08/10/2012	08/10/2042	60,000,000	2,490,000
5	First Mortgage Bonds 4.30% (Montana)		40,000,000		251,114			08/10/2012	08/10/2052	08/10/2012	08/10/2052	40,000,000	1,720,000
6	First Mortgage Bonds 4.85% (Montana)		15,000,000		70,047			12/19/2013	12/19/2043	12/19/2013	12/19/2043	15,000,000	727,500
7	First Mortgage Bonds 3.99% (Montana)		35,000,000		163,444			12/19/2013	12/19/2028	12/19/2013	12/19/2028	35,000,000	1,396,500
8	First Mortgage Bonds 4.176% (Montana)		450,000,000		4,927,101			11/14/2014	11/15/2044	11/14/2014	11/15/2044	450,000,000	18,792,000
9	First Mortgage Bonds 3.11% (Montana)		75,000,000		4,137,235			06/23/2015	07/01/2025	07/01/2015	07/01/2025	75,000,000	2,332,500
10	First Mortgage Bonds 4.11% (Montana)		125,000,000		6,895,391			06/23/2015	07/01/2045	07/01/2015	07/01/2045	125,000,000	5,137,500
11	First Mortgage Bonds 4.03% (Montana)		250,000,000		17,138,156			11/06/2017	11/06/2047	11/06/2017	11/06/2047	250,000,000	10,075,000
12	First Mortgage Bonds 3.98% (Montana) A		50,000,000		322,669			06/26/2019	06/26/2049	06/26/2019	06/26/2049	50,000,000	1,990,000
13	First Mortgage Bonds 3.98% (Montana) B		100,000,000		645,339			09/17/2019	09/17/2049	09/17/2019	09/17/2049	100,000,000	3,980,000
14	First Mortgage Bonds 3.21% (Montana)		100,000,000		422,199			05/15/2020	05/15/2030	05/15/2020	05/15/2030	100,000,000	3,210,000
15	First Mortgage Bonds 1.00% (Montana)		100,000,000		557,601			03/26/2021	03/26/2024	03/26/2021	03/26/2024	0	236,301
16	First Mortgage Bonds 5.57% (Montana)		239,000,000		1,158,989			03/30/2023	03/30/2033	03/30/2023	03/30/2033	239,000,000	13,312,300
17	First Mortgage Bonds 5.56% (Montana)		175,000,000		792,992			05/28/2024	03/28/2031	05/28/2024	03/28/2031	175,000,000	7,378,583
18	Pollution Control Revenue Bonds - 3.88% Series, City of Forsyth (Montana)		144,660,000		1,555,503							144,660,000	5,605,575
19	Subtotal		2,174,660,000		40,874,033	4,730,180						2,074,660,000	89,590,359
20	Reacquired Bonds (Account 222)
21
22
23
24	Subtotal
25	Advances from Associated Companies (Account 223)
26
27
28
29	Subtotal
30	Other Long Term Debt (Account 224)
31	Senior Unsecured Revolving Line of Credit ($425m)		342,000,000					11/29/2023	11/29/2028	11/29/2023	11/29/2028	342,000,000	13,385,890
32	Interest Rate Hedge Amortizations												613,744
33	Subtotal		342,000,000									342,000,000	13,999,634
33	TOTAL		2,516,660,000									2,416,660,000	103,589,993

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

FOOTNOTE DATA

(a) Concept: BondsPrincipalAmountIssued

As issuances are redeemed, the related expense and premium or discount, as applicable, is charged to Loss on Reacquired Debt.

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

RECONCILIATION OF REPORTED NET INCOME WITH TAXABLE INCOME FOR FEDERAL INCOME TAXES
Report the reconciliation of reported net income for the year with taxable income used in computing Federal income tax accruals and show computation of such tax accruals. Include in the reconciliation, as far as practicable, the same detail as furnished on Schedule M-1 of the tax return for the year. Submit a reconciliation even though there is no taxable income for the year. Indicate clearly the nature of each reconciling amount. If the utility is a member of a group which files a consolidated Federal tax return, reconcile reported net income with taxable net income as if a separate return were to be field, indicating, however, intercompany amounts to be eliminated in such a consolidated return. State names of group member, tax assigned to each group member, and basis of allocation, assignment, or sharing of the consolidated tax among the group members. A substitute page, designed to meet a particular need of a company, may be used as Long as the data is consistent and meets the requirements of the above instructions. For electronic reporting purposes complete Line 27 and provide the substitute Page in the context of a footnote.
Line No.	Particulars (Details) (a)	Amount (b)
1	Net Income for the Year (Page 117)	180,078,441
2	Reconciling Items for the Year
3
4	Taxable Income Not Reported on Books
5	Equity Earnings of Subsidiaries	1,443,963
9	Deductions Recorded on Books Not Deducted for Return
10	Meals and Entertainment	1,019,693
11	Non-Deductible Dues/Lobbying Expense/Penalties/Professional Fees/Non-Deductible Parking/GILTI Inclusion	634,408
12	Federal Income Taxes	15,122,465
13	State Tax Adjustment	3,742,953
14	Income Recorded on Books Not Included in Return
15
16
17
18
19	Deductions on Return Not Charged Against Book Income
20	Net Tax Greater Than Book Depreciation	81,374,262
21	Amortization of Intangibles	215,461
22	Plant Flow Through Items	93,535,777
23	Reserves & Accruals	14,545,490
24	Deferred Book Revenue & Gains	46,232,446
25	Contributions & Advances for Construction	15,752,705
26	NOL Carryforward	29,829,128
27	Other Miscellaneous	1,634,802
27	Federal Tax Net Income	8,816,702
28	Show Computation of Tax:
29	Federal tax Expense/(Benefit) @ 21%	1,851,507

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

TAXES ACCRUED, PREPAID AND CHARGES DURING YEAR
Give particulars (details) of the combined prepaid and accrued tax accounts and show the total taxes charged to operations and other accounts during the year. Do not include gasoline and other sales taxes which have been charged to the accounts to which the taxed material was charged. If the actual, or estimated amounts of such taxes are known, show the amounts in a footnote and designate whether estimated or actual amounts. Include on this page, taxes paid during the year and charged direct to final accounts, (not charged to prepaid or accrued taxes.) Enter the amounts in both columns (g) and (h). The balancing of this page is not affected by the inclusion of these taxes. Include in column (g) taxes charged during the year, taxes charged to operations and other accounts through (a) accruals credited to taxes accrued, (b)amounts credited to proportions of prepaid taxes chargeable to current year, and (c) taxes paid and charged direct to operations or accounts other than accrued and prepaid tax accounts. List the aggregate of each kind of tax in such manner that the total tax for each State and subdivision can readily be ascertained. If any tax (exclude Federal and State income taxes) covers more than one year, show the required information separately for each tax year, identifying the year in column (d). Enter all adjustments of the accrued and prepaid tax accounts in column (i) and explain each adjustment in a foot- note. Designate debit adjustments by parentheses. Do not include on this page entries with respect to deferred income taxes or taxes collected through payroll deductions or otherwise pending transmittal of such taxes to the taxing authority. Report in columns (l) through (o) how the taxes were distributed. Report in column (o) only the amounts charged to Accounts 408.1 and 409.1 pertaining to electric operations. Report in column (l) the amounts charged to Accounts 408.1 and 409.1 pertaining to other utility departments and amounts charged to Accounts 408.2 and 409.2. Also shown in column (o) the taxes charged to utility plant or other balance sheet accounts. For any tax apportioned to more than one utility department or account, state in a footnote the basis (necessity) of apportioning such tax.
					BALANCE AT BEGINNING OF YEAR					BALANCE AT END OF YEAR		DISTRIBUTION OF TAXES CHARGED
Line No.	DescriptionOfTaxesAccruedPrepaidAndCharged Kind of Tax (See Instruction 5) (a)	TypeOfTax Type of Tax (b)	TaxJurisdiction State (c)	TaxYear Tax Year (d)	TaxesAccrued Taxes Accrued (Account 236) (e)	PrepaidTaxes Prepaid Taxes (Include in Account 165) (f)	TaxesCharged Taxes Charged During Year (g)	TaxesPaid Taxes Paid During Year (h)	TaxAdjustments Adjustments (i)	TaxesAccrued Taxes Accrued (Account 236) (j)	PrepaidTaxes Prepaid Taxes (Included in Account 165) (k)	TaxesAccruedPrepaidAndCharged Electric (Account 408.1, 409.1) (l)	IncomeTaxesExtraordinaryItems Extraordinary Items (Account 409.3) (m)	AdjustmentsToRetainedEarnings Adjustment to Ret. Earnings (Account 439) (n)	TaxesIncurredOther Other (o)
1	FICA and Medicare	Federal Tax	Montana	2024	0		10,710,823	10,710,823		0		5,687,811			5,023,012
2	State Income Tax	State Tax	Montana	2024	4,825,768		34,077		(a) 4,837,568	45,877		385,059			419,136
3	State Income Tax	State Tax	South Dakota/Nebraska	2024	187,000				(b) 187,000	0		0			0
4	Hydro Invasive Species Tax	Other Taxes	Montana	2023	182,627			182,627		0		0			0
5	Hydro Invasive Species Tax	Other Taxes	Montana	2024	0		738,465	553,849		184,616		738,465			0
6	Heavy Highway Tax	Other Taxes	Montana	2024	0		1,100	1,100		0		760			340
7	WET Tax	Other Taxes	Montana	2023	452,825			452,825		0		0			0
8	WET Tax	Other Taxes	Montana	2024	0		2,549,315	2,116,638		432,677		1,418,857			1,130,458
9	EELT Tax	Other Taxes	Montana	2023	244,453			244,453		0		0			0
10	EELT Tax	Other Taxes	Montana	2024	0		879,771	648,438		231,333		867,658			12,113
11	Consumer Counsel	Other Taxes	Montana	2023	160,063			160,063		0		0			0
12	Consumer Counsel	Other Taxes	Montana	2024	0		627,854	505,819		122,035		450,380			177,474
13	Montana Public Service Commission	Other Taxes	Montana	2023	986,267			986,267		0		0			0
14	Montana Public Service Commission	Other Taxes	Montana	2024	0		3,788,748	3,116,761		671,987		2,784,075			1,004,673
15	Gross Receipts Tax	Other Taxes	South Dakota	2023	375,390				(c) 375,390	0		0			0
16	Property Tax	Property Tax	Montana	2023	72,794,060			72,794,060		0		0			0
17	Property Tax	Property Tax	Montana	2024	0		150,259,585	75,455,316		74,804,269		114,594,043			35,665,542
18	Property Tax - Crow Tribe	Property Tax	Montana	2024	0		209,784	209,784		0		74,880			134,904
19	Property Tax - Blackfoot	Property Tax	Montana	2024	0		757,600	757,600		0		0			757,600
20	Property Tax	Property Tax	South Dakota	2023	5,229,950				(d) 5,229,950	0					0
21	Property Tax	Property Tax	Nebraska	2023	818,386				(e) 818,386	0		0
22	Property Tax	Property Tax	North Dakota	2023	16,119				(f) 16,119	0					0
23	Property Tax	Property Tax	Iowa	2022	51,282				(g) 51,282	0					0
24	Property Tax	Property Tax	Iowa	2023	81,520				(h) 81,520	0		0			0
25	Federal Unemplyment Tax	Unemployment Tax	Montana	2023	1,337			1,337		0		0			0
26	Federal Unemplyment Tax	Unemployment Tax	Montana	2024	0		61,528	60,361		1,167		18,595			42,933
27	Federal Unemplyment Tax	Unemployment Tax	South Dakota	2023	477				(i) 477	0		0			0
28	State Unemployment Tax	Unemployment Tax	Montana	2023	18,449			18,449		0		0			0
29	State Unemployment Tax	Unemployment Tax	Montana	2024	0		473,487	452,755		20,732		143,694			329,793
30	State Unemployment Tax	Unemployment Tax	South Dakota	2023	529				(j) 529	0		0			0
31	Use Tax	Sales And Use Tax	Wyoming	2023	6,946			6,946		0		0			0
32	Use Tax	Sales And Use Tax	Wyoming	2024	0		523	523		0		0			523
33	Use Tax	Sales And Use Tax	South Dakota	2023	84,565			19,130	(k) 65,435	0		0			0
34	Use Tax	Sales And Use Tax	South Dakota	2024			190,736	183,478		7,258		0			190,736
35	Federal Income Tax	Income Tax	Montana	2023	500,000		847,887	15,262	(l) 94,646	427,271		397,921			1,245,808
36	Delaware Franchise Tax	Franchise Tax	Montana	2024	0		303,568	303,568		0		225,180			78,388
37	Electric Vehicle Charging Station Tax		Montana	2024	0		47,515	35,698		11,817					47,515
40	TOTAL				75,992,477		172,482,366	169,993,930	1,519,874	(m) 76,961,039		(n) 126,221,418			46,260,948

Name of Respondent:

NorthWestern Corporation

This report is:

(1)

☑ An Original

(2)

☐ A Resubmission

Date of Report:

12/31/2024

Year/Period of Report

End of:

2024

FOOTNOTE DATA

(a) Concept: TaxAdjustments

State refund

(b) Concept: TaxAdjustments