Officials with the U.S. Mine Safety and Health Administration say the men were burned Tuesday about 10:50 a.m. at a coal truck crusher dump while they were working to change a bearing on a chain conveyor at the North Antelope Rochelle Mine.
They tell the Casper Star-Tribune that coal dust was ignited by embers and a burner used to heat the bearing race.
The miners were transported to Campbell County Memorial Hospital in Gillette and then sent to a hospital in Greeley, Colo.
Their names were not released.
The mine is owned by St. Louis-based Peabody Energy Corp.
Peabody spokeswoman Charlene Murdock says the incident is under investigation.
Information from: Casper (Wyo.) Star-Tribune