Jonathan Ambarian

HELENA (KPAX) — At the end of the year, NorthWestern Energy is set to take over majority ownership of the Colstrip power plant. Now, the company is asking regulators to sign off on their plans for the newly acquired power, but some opponents are claiming the deals haven’t gotten the oversight they should.

The coal-fired Colstrip Steam Electric Station has a complex ownership structure, with six energy companies holding shares. Currently, NorthWestern controls 222 megawatts of electricity, or 15% of the plant’s generating capacity. Starting Jan. 1, 2026, they will acquire another 222 megawatts currently held by Avista Corp. and 370 megawatts from Puget Sound Energy, bringing the company up to 55% ownership.

NorthWestern announced it was acquiring Avista’s share of t

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