Citing the termination of its coal supply agreement with the Tennessee Valley Authority as well as the "continued weakness" in coal demand in the region Bowie Resources Partners, the owners of the Bowie #2 coal mine in western Colorado announced the elimination of 150 jobs at the mine. A 40 percent reduction of its workforce, The Denver Business Journal reported.

“We want to thank the hardworking employees at Bowie #2 for their dedication and their strong commitment to running a safe and productive operation. We hope to retain as many of these valued members of the Bowie team as we can — and plan to offer positions at Bowie Resources Partners (BRP’s) other mining operations to as many affected employees as possible,” DiClaudio said.

The Delta County mine, one of Colorado's biggest coal operations, had 369 miners on its workforce in July, according to statistics from the Colorado Division of Reclamation, Mining and Safety, part of the Colorado Department of Natural Resources.

The mine had produced about 1.5 million tons of coal in 2014 through the end of July. All of Colorado's coal mines had produced about 12.9 million tons of coal through the first seven months of July, according to the state’s figures.

“Although we are reducing production at Bowie #2 at this time, we believe there may be opportunities for Colorado coal in the future – both here at home and in the global marketplace,” DiClaudio said.

Bowie’s announcement indicated the company will give laid-off employees 60 days of wages and benefits in addition to a severance package. Relocation assistance will also be available to Bowie #2 employees who fill open positions at other company mines.

Colorado coal production hit a peak of nearly 40 million tons in 2004 and has fallen by more than 40 percent since then, according to the Colorado Mining Association.

The association said the Bowie mine produced about 3.3 million tons of coal in 2013 and that the layoffs will cut production at the mine by about 33 percent.

The drop in Colorado's coal production is due largely to the climate of “uncertainty” regarding future regulations governing carbon emissions from power plants, according to the association.

Specifically, the association said Colorado's Clean Air-Clean Jobs Act of 2010, which led Xcel Energy Inc. and Black Hills Corp. to shut down coal-fired power plants and replace the generation with natural gas plants, for hurting the state's mining industry.

“Since 2010, the state of Colorado has enacted laws and initiated policies to phase, if not drive, affordable and clean Colorado coal out of the energy mix. These 150 miners are among the many casualties,” said Stuart Sanderson, CMA President.

On the federal front, the U.S. Environmental Protection Agency in June proposed rules to cut the nation's carbon dioxide production by 30 percent below 2005 levels by 2030.

The layoffs at the Bowie #2 mine come less than a year after 300 jobs were lost when Oxbow Mining LLC said in December 2013 it planned to idle its Elk Creek coal mine in Gunnison County.