Conservation groups have sued the government to force federal officials to undertake the first broad environmental review of the government's coal-leasing program in decades.
Friends of the Earth and the Western Organization of Resource Councils filed the lawsuit Tuesday in U.S. District Court in Washington, D.C.
It's being paid for by the philanthropic foundation of Microsoft founder Paul Allen.
Supporters of the lawsuit said there hasn't been a comprehensive review of the government's coal program since 1979. That's before climate-changing gases produced by burning coal emerged as a significant public concern.
The U.S. Bureau of Land Management has been reviewing its coal-leasing program since a government investigation last year revealed officials accepted below-market bids in some coal sales.
BLM spokesman Jeff Krauss declined to comment on Tuesday's lawsuit.