DENVER (AP) - A conservation group is heading to court over plans to explore for molybdenum (meh-LIB’-deh-nem) at an old mining site near Crested Butte.

The High Country Citizens’ Alliance filed a lawsuit in Denver last week over work planned at Mount Emmons.

It says Colorado mining officials should have required U.S. Energy Corp. to post enough bond to cover water treatment costs from its proposed work before approving the company’s plans.

The lawsuit asks a judge to order the state to calculate how much the Riverton, Wyo.-based company should put up.

The Colorado Mined Land Reclamation Board rejected a similar request from the group in January.

U.S. Energy CEO Keith Larsen said Monday he thought the board’s decision was appropriate. He says the company doesn’t comment on pending litigation.

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