BOISE, Idaho (AP) — Three environmental groups have filed a lawsuit challenging the U.S. Forest Service's approval of a mining company's plan to do exploratory drilling about 55 miles northeast of Boise.

The Idaho Conservation League, Idaho Rivers United and Golden Eagle Audubon Society in the lawsuit filed Friday in U.S. District Court say the federal agency violated environmental laws in approving the project.

The Forest Service in October approved Idaho CuMo Mining Corporation's plan that includes building about 10 miles of roads and up to 137 drill pads for up to 259 drill holes in the Boise National Forest.

The company wants to determine if molybdenum, copper and silver exist in sufficient quantities to go forward with an open-pit mine. The Forest Service declined to comment Wednesday.