A federal judge blocked a proposed expansion of an underground coal mine in Montana because the project’s climate change impacts were not adequately considered by the Trump administration.

U.S. District Judge Donald Molloy ruled Monday that the federal Office of Surface Mining (OSM) inflated the economic benefits of the 176 million-ton expansion of Signal Peak Energy’s Bull Mountain coal mine while minimizing its environmental impact. The judge ordered the company to stop mining in the proposed expansion area pending further studies.

The OSM’s approval would have allowed the mine to become the largest underground coal mine in the country based on annual production. Approximately 95 percent of the coal from Bull Mountain is exported, primarily to Asian markets.

The Sierra Club, Montana Environmental Information Center, and Montana Elders for a Livable Tomorrow were co-plaintiffs in the case, which was brought by the Western Environmental Law Center.


“Federal agencies have a legal responsibility to account for the heavy burden that burning coal places on every aspect of public health and our economy,” Bill Corcoran, regional campaign director for the Sierra Club’s Beyond Coal campaign, said in a statement Tuesday. “Federal agencies must act on that reality, not stick their heads in the sand and invent ways to ignore it.”

A Signal Peak spokesperson told a local news outlet that the company will evaluate all of its options in the coming weeks.

The judge specifically rejected the OSM’s decision to tout purported economic benefits, such as local taxes, while simultaneously refusing to use the social cost of carbon, or any other method, to analyze those harms. He also ruled that the OSM did not properly consider the air quality and safety impacts of additional uncovered coal trains travelling through communities across the Pacific Northwest.

“A federal agency should not be allowed to put its thumb on the scale when making decisions of this magnitude. The law requires, and the public deserves, an honest analysis of the risks and the benefits of proposals such as these,” said Anne Hedges, with the Montana Environmental Information Center.


Meanwhile, the state of Wyoming’s Environmental Quality Council earlier this month found deficiencies in an application for Ramaco Carbon’s proposed Brook Mine, which would be the first coal mine in Wyoming in more than three decades, the Casper Star Tribune reported.

The council ruled that the company’s plan lacked a long-term plan to provide water to nearby homeowners after other mining activity affected their well water. The council also noted the lack of blasting limits and the increased risk that land could sink in the area. The company is expected to resubmit its application but will likely face opposition from local homeowners.