Environmentalists have asked Montana regulators to suspend permits for two silver mines citing concerns over the track record of the president of the company behind the proposals.
Attorneys for Earthworks, the Clark Fork Coalition and three other groups on Monday pressed officials to enforce a state law that blocks individuals who fail to reclaim old mines from starting new ones.
Hecla Mining Company of Idaho is proposing the Rock Creek and Montanore mines in northwest Montana.
Its president, Phillips Baker, was formerly an executive with Pegasus Gold Inc., which operated three mines that environmentalists say left surrounding waterways polluted.
Hecla spokesman Luke Russell said the environmentalists were misconstruing the law to block the new mines.
Department of Environmental Quality spokeswoman Kristi Ponozzo said the agency was reviewing the environmentalists' request.