HELENA - Two more environmental groups are suing the Montana Land Board for leasing the state's Otter Creek tracts to a St. Louis-based coal giant.
The Montana Environmental Information Center and Sierra Club say the board never examined the potentially devastating consequences for the environment.
The groups say almost all the coal would go to power plants that would emit billions of tons of carbon dioxide, a greenhouse gas that contributes to global warming.
The lawsuit filed Friday is the second challenging the Otter Creek deal. The Northern Plains Resource Council and the National Wildlife Federation filed suit on Wednesday.
The Land Board voted in March to lease 572 million tons of coal reserves near the Wyoming border to Arch Coal for $86 million and future royalties.