SHERIDAN — Spring Creek Mine in Montana has undergone an “immediate and indefinite” shutdown of operations, according to a press release from Navajo Transitional Energy, the company that took control of the mine yesterday.

The release said the shutdown is the result of a dispute with the Montana Department of Environmental Quality over the Navajo tribe’s sovereign immunity. NTEC claims the agency has refused to issue NTEC, a limited liability company wholly owned by the Navajo Nation, an operating permit for the mine unless the company agrees to completely waive its sovereign immunity.

The company has offered to waive partial immunity, which it claims would allow it to be regulated under Montana laws, according to the release.

“We are shocked and disappointed that the State is taking this position and putting the future of Spring Creek at risk,” said NTEC Chairman Tim McLaughlin in the release.

As of 10 a.m. Thursday morning, the Montana DEQ has not responded to a request for comment.