Our Company

For more than 100 years, NorthWestern Energy has been committed to delivering safe, reliable and innovative energy solutions.

We serve gas and electric to customers in the western two-thirds of Montana and eastern South Dakota. We also have gas service in Nebraska and serve electricity to Yellowstone National Park.

NorthWestern owns and operates a diverse generation fleet of wind, water, natural gas and coal-fired resources and the high-voltage electric transmission system and distribution system. We also own and operate natural gas production, transmission and distribution systems.

Enriching Lives Through a Safe, Sustainable Energy Future

A map showing NorthWestern Energy's service territory in Montana, Nebraska and South Dakota.

Enriching Lives Through a Safe, Sustainable Energy Future

NorthWestern Energy has provided reliable and affordable electricity and natural gas to customers in Montana, South Dakota and Nebraska for more than 100 years.

Our Commitment to Sustainability

Sustainability means meeting today’s needs while planning for tomorrow’s as well.

Our vision

Enriching lives through a safe sustainable energy future.

Our mission

Working together to provide safe, reliable and innovative energy solutions that create value for customers, communities, employees, and investors.

Our values

SERVICE: Safety, Excellence, Respect, Value, Integrity, Community, Environment

Our Natural Gas and Electric Service

NorthWestern Energy serves 341 communities in Montana, South Dakota and Yellowstone National Park with safe and reliable electricity. We serve natural gas to 202 communities in Montana, South Dakota and Nebraska.

Our Hydro Facilities

Our carbon-free hydro system is the foundation of our energy generation portfolio in Montana. In 2024, nearly 34% of our electricity for Montana customers came from our hydro facilities.

Giving Back to Our Communities

NorthWestern Energy is committed to being a good corporate citizen of all the communities we serve. In 2024, we gave $2.3 million in charitable donations and community support.

Delivering a Bright Future

Employee Noel Jacobson wears a hard hat and smiles in Power Park.

Delivering a Bright Future

We won't stop working until the future is as bright as it can be.

Where Does Your Energy Come From?

We provide safe, reliable energy through a balanced mix of clean energy and traditional resources.

Harmful algal blooms confirmed on Hebgen Reservoir- advisory issued

Date: Aug 21, 2025

TYPE: News

Bozeman, Mont. – Aug. 21, 2025 – Harmful algal blooms (HABs) are present on Hebgen Reservoir in the Rainbow Point Campground area. Routine monitoring of Hebgen has confirmed the presence of anatoxin-a which poses a risk to people, pets, and livestock.

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. Ingestion or prolonged contact with the algal bloom may result in illness, with impacts such as muscle twitching, staggering, convulsions, paralysis, and death.

Children and pets are more likely to ingest HAB infested water.

Toxin exposure can occur in humans from recreational activities where water might be ingested such as swimming, wind surfing, jet skiing, and water skiing.  Children and pets are more likely to ingest HAB infested water 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.

Blue-green 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 public access points in the Rainbow Point Campground area warning the public that toxic algae has been identified in the water in these areas. At this time there are no other identified blooms affecting other areas of the reservoir.

NorthWestern Energy is 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 www.hab.mt.gov or call 1-888-849-2938.  You may also report a suspected HAB by calling the Gallatin City-County Health Department Environmental Health at 406-582-3120. The Gallatin City-County Health Department has resources for water quality on their website, www.healthygallatin.org.

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About NorthWestern Energy (Nasdaq: NWE)

NorthWestern provides electricity and / or natural gas to approximately 842,000 customers in Montana, South Dakota, Nebraska, and Yellowstone National Park. We have generated and distributed electricity in South Dakota and distributed natural gas in South Dakota and Nebraska since 1923 and have generated and distributed electricity and distributed natural gas in Montana since 2002. More information on NorthWestern is available on the company’s website at www.northwesternenergy.com.

 Media Contacts:

NorthWestern Energy

Jo Dee Black

866-622-8081

jodee.black@northwestern.com

Montana Department of Environmental Quality

Tiffany Lyden

406-444-3576

tiffany.lyden@mt.gov

Gallatin City-County Health Department

Holly Whaley

406-579-4232

holly.whaley@gallatin.mt.gov