GILLETTE – Nearly 480 coal mine workers in northeast Wyoming are being laid off.

According to several media reports, the St. Louis-based Peabody Energy Corp., the largest U.S. coal producer, said it would lay off about 235 employees at a mine in the Powder River basin.

The reductions affect about 15 percent of the workforce at the North Antelope Rochelle mine in the basin straddling Montana and Wyoming, the company said on Thursday.

After reduction, Peabody’s Powder River basin operations will employ about 1,500 workers, of which about 1,150 will be at North Antelope, the coal miner said.

A second company, the Creve Coeur-based Arch Coal, announced it is laying off 243 workers at its Black Thursday mine, representing about 15 percent if its nearly 1,600 workers at the mine.

Both mines are located in the coal rich Powder River Basin in Campbell County. Together, they produce about 200 million tons of coal a year.

Two wees ago it was announced Peabody was a bankruptcy risk and Arch Coal is currently organizing in bankruptcy court.