The body of a man was discovered on Thursday morning at the bottom of a Rosebud Mine pit, Rosebud County Sheriff Allen Fulton said.
"It wasn't something that happened today," Fulton said of the death. "It (the body) had been there for a while."
An employee at the mine located outside of Colstrip found the body at about 11 a.m.
Initial indications don't suggest foul play, but the death is being investigated in order to rule out homicide, Fulton said.
"It does not appear to be an employee," Fulton said, adding that investigators have an idea of who it might be but are still waiting to confirm.
Less than two weeks ago Michael Ramsey, a 62-year-old coal miner, died in an incident at the mine involving a dump truck.
"This has nothing to do with that," Fulton said.
Personnel from the U.S. Department of Labor Mining Safety and Health Administration were already on-site Thursday regarding the other incident and have been alerted of the discovery of the new body, Fulton said.
An autopsy is scheduled for Friday in Billings.