Conservation groups want a Montana court to cancel the approval of the long-disputed Black Butte copper mine, saying it would pollute a tributary of the Smith River, one of the state's most popular recreational rivers.
Montana Trout Unlimited and other groups filed a lawsuit Thursday alleging state officials did not thoroughly study the environmental harm that could result from the Black Butte copper mine in central Montana.
The Montana Department of Environmental Protection and Tintina Montana Resources were named as defendants in the complaint filed in state district court in Meagher County.
State officials said in approving the mine in April that it would have to abide by some of the most stringent conditions ever issued for a hardrock mine in Montana.
A Tintina subsidiary is seeking about $300 million to develop the project, which is expected to bring in about $2 billion in revenue.
Opponents of the mine say it will pollute a tributary of the Smith River. They point to the ongoing mining pollution in other parts of Montana that started when companies went bankrupt and state and federal agencies had to take over cleanup efforts.
The 110-mile Smith River runs through a limestone canyon and a scenic valley before flowing into the Missouri River south of Great Falls. The waterway is so popular, the state holds an annual lottery for permits to float down it.
The proposed underground mine is on private land north of White Sulphur Springs and would extract 15.3 million tons of copper-laden rock and waste over 15 years — roughly 440 tons a day.