News, Articles & Events

Bright Magazine

Bright Magazine showcases our sustainability efforts and the exciting work going on at NorthWestern Energy. Subscribe or read online.

Bob Glanzer Generating Station

Our new Bob Glanzer Generating Station is helping us move toward our clean energy future.
Ennis Lake

Harmful algae blooms detected at Ennis Lake – advisory issued

Date: Sep 1, 2022

TYPE: News

Bozeman, Mont. – Sept. 1, 2022– Harmful algae blooms (HAB) are present along the Kobayashi Beach and other areas of the north shore of Ennis Lake, west of Madison Dam. Routine monitoring and field testing in the Kobayashi Beach and Meadow Lake Campground areas have detected the presence of an algal toxin, Anatoxin-a, that poses a risk to people, pets, and livestock.

Ingestion or prolonged contact with the algal bloom may result in illness, with signs such as muscle twitching, staggering, convulsions, paralysis and death. Importantly, children and pets are more likely to ingest HAB infested waters because they spend most of their time wading in the shallow waters where algae can accumulate, and they have less control over how much water they ingest. Animals and livestock that drink large amounts of contaminated water, and pets that collect scum on their fur and then ingest it by licking, are at high risk of toxin exposure. Toxin exposure can occur in humans from recreational activities where water might be ingested such as swimming, wind surfing, jet skiing, and water skiing. 

Health experts recommend people not swim or take part in activities likely to result in exposure to the toxin in areas where the algal bloom is present. Additionally, pets and livestock should be prevented from entering the water in that area.

HABs are caused by blue-green algae that are native to Montana’s freshwater lakes and reservoirs. Not all varieties of blue-green algae are harmful, but some can produce dangerous toxins. Bluegreen algal blooms often look like pea soup, grass clippings or green latex paint. The algae are usually suspended in the water or appear as floating mats.

Advisory signs are at the Clute’s Landing, Meadow Lake Campground, and Kobayashi Beach public access points warning the public that toxic algae has been identified in the water in these areas. NorthWestern Energy and the Montana Department of Environmental Quality (DEQ) are monitoring the blooms and will provide updates if additional restrictions are implemented for public safety.

Suspect a HAB? When in doubt, stay out. Do not drink, swallow, or swim in water that shows signs of a HAB and be sure to keep kids, pets, and livestock out too. If you suspect a HAB-related illness in a person or animal call Poison Control 1-800-222-1222 and seek medical attention.

Report a suspected HAB at or call 1-888-849-2938. You may also report a suspected HAB by calling the Madison County Health Department at 406- 465-7339. Follow NWE on Facebook or on Twitter (@NWEinfo) and the Madison County Health Department (@madisoncountypublichealthdept).

Follow us on Facebook or on Twitter (@NWEinfo).

About NorthWestern Energy (Nasdaq: NWE)

NorthWestern Corporation, doing business as NorthWestern Energy, provides essential energy infrastructure and valuable services that enrich lives and empower communities while serving as long-term partners to our customers and communities. We are working to deliver safe, reliable, and innovative energy solutions that create value for customers, communities, employees, and investors. This includes bridging our history as a regulated utility safely providing low-cost and reliable service with our future as a globally-aware company offering a broader array of services performed by highly-adaptable and skilled employees. We provide electricity and / or natural gas to approximately 753,600 customers in Montana, South Dakota, Nebraska and Yellowstone National Park. We have provided service in South Dakota and Nebraska since 1923 and in Montana since 2002. More information is available on the company's Web site at


Media Contacts:  


NorthWestern Energy  

Jo Dee Black



Montana Department of Environmental Quality, Watershed Protection Section

Moira Davin 406-461-2503


Madison County Health Department

Zach Kozicky