Colstrip Power Plant, Montana

Owned by several different companies, this large coal-fired power plant has four units. Units 1 and 2 opened in 1975 and 1976, and shut down in 2020. Units 3 and 4 opened in 1984 and 1986 and continue to operate. The power plant is supplied by the Rosebud Coal Mine, next door (which declared bankruptcy in 2018, but continues to supply the plant with new owners). Water to generate steam comes from the Yellowstone River, 30 miles away, through an underground pipeline. The water is stored in a holding reservoir, Castle Rock Lake, which is used for recreation by the town of Colstrip’s 2,000 residents. The town and mine were established by Northern Pacific Railway in the 1920s, to supply coal for its trains, powered by coal at that time.