Montana
- 7,000 miles of transmission lines and associated terminal facilities
- Voltage levels ranging from 50 kilovolts to 500 kilovolts
- 272 circuit segments
- 125,000 transmission poles
- Extends throughout the western two-thirds of Montana from Colstrip in the east to Thompson Falls in the west
- Jointly owns a 500-kilovolt transmission system that transfers electricity generated from the 2,180 megawatt Colstrip generation facility to markets within the state and west of Montana
- Interconnections to five major nonaffiliated transmission systems located in the Western Electricity Coordinating Council (WECC) area
- One interconnection to a system that connects with the Mid-Continent Area Power Pool (MAPP) region
- Our electric transmission system within Montana is strategically located to allow for the purchase and delivery of power in diverse markets — the Pacific Northwest, the desert Southwest and California, the Colorado area, and the MAPP region.
Transmission reservations for service over the Montana system occur on NorthWestern Energy's Open Access Same-Time Information System (OASIS). Transmission service for both wholesale and deregulated retail access are provided under the FERC electric Open Access Transmission Tariff (OATT).
For more information about our Electric Transmission Services, you may contact us via e-mail or call (406) 497-4717.
FERC Order 890 requires transmission providers to post on OASIS all of their business rules, practices, and standards that relate to transmission services provided under the pro forma OATT. Below are the links to NorthWestern Energy's documents.
South Dakota
- Interconnections and pooling arrangements with Otter Tail Power Company, Montana-Dakota Utilities Co., Xcel Energy, Inc. and the Western Area Power Administration
- Emergency interconnections with East River Electric Cooperative, Inc. and West Central Electric Cooperative
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