Billings Federal District Court Judge Susan Watters ruled that the Department of Interior’s Office of Surface Mining (OSM or the federal defendants) erred in approving Western Rosebud Mining’s Area F permit application in June 2019. The court ruled that the OSM failed to consider the impact on the Yellowstone River and climate change.

The expansion would allow Rosebud to mine an additional 6,500 acres containing about 70 million tons of coal, most of which would be burned by the Colstrip power plant to generate electricity. The mine and the power plant are both located near Colstrip, Montana. Environmental activists claim that the Colstrip power plant diverts 25,000 to 50,000 acre-feet of water from the Yellowstone River annually and they would like to do away with coal-fired power entirely for the sake of the planet.

The judge remanded the Area F environmental impact statement (EIS) to OSM and ordered the federal defendants to remedy its analysis of the cumulative effects of the mine on surface water, indirect effects of water withdrawals from the Yellowstone River, the socioeconomic impacts of greenhouse gas emissions, and consider alternatives to conform with the National Environmental Policy Act (NEPA). The judge gave the federal defendants 19 months to complete a corrective NEPA analysis and prepare an updated EIS.