BILLINGS, Mont. (AP) — Opponents of mining outside Yellowstone National Park are challenging a decision by Montana environmental regulators to allow a Canadian company to explore for precious metals just north of the park.

The Park County Environmental Council and Greater Yellowstone Coalition sued the Montana Department of Environmental Quality and Lucky Minerals, Inc. on Friday in state District Court in Park County.

Lucky Minerals was given approval to drill on private land in the Absaroka Mountains southeast of Emigrant to gauge its copper, gold, silver and molybdenum deposits.

Plaintiff's attorney Jenny Harbine says the state's analysis of the company's proposal should have considered the potential for a large-scale mine to be built at the exploration site.

Representatives of the state and company did not immediately respond to requests for comment.