Matthew Brown

Associated Press

BILLINGS, Mont. (AP) — Montana regulators have reached a deal allowing the state to enforce environmental laws at a large coal mine bought by a Navajo-owned company, officials said Thursday.

For months, executives from the Navajo Transitional Energy Company and state officials had been unable to resolve demands the company waive its immunity as a tribal entity from future lawsuits.

The mine shut down briefly in October when the dispute over sovereignty first emerged. Thursday’s agreement came a day before a temporary waiver agreement was set to expire.

The Navajo company bought the 275-worker Spring Creek strip mine along the Wyoming border and two mines in Wyoming last year from bankrupt Cloud Peak Energy.