Montana environmental officials proposed approval of a major expansion of the Spring Creek Mine, the largest coal mine in the state.

The 65 Mt (72 million st) expansion will occur within the mine will occur within the mine's existing permit boundary, said Jen Lane with the Montana Department of Environmental Quality. The mine is one of three mines in the Powder River Basin that Navajo Traditional Energy Co. purchased from Cloud Peak Energy (ME, Aug. 20, 2019).

The Associated Press reported that the expansion will disturb 2.4 km (1.5 miles) of additional land and extend the life of the mine by four years, to approximately 2031.

Spring Creek in 2017 ranked as the 10th largest coal mine in the United States, producing almost 12 Mt (13 million st) of coal.

Navajo Transitional Energy spokesman Erny Zah declined to say if the company would retain all of the employees from the three mines it purchased from Cloud Peak which had roughly 1,200 employees, but not all work at the mines.

"All that's being worked out as we get closer to the close date," Zah said.

The sale of the three mines is expected to close in October and would make the Navajo the third largest coal producer in the United States.

Its mining company also operates the Navajo mine near the Arizona-New Mexico border that serves the nearby Four Corners Power Plant. The power plant is one of three in the region that are scaling back operations as utilities shift toward natural gas and renewable energy sources.

The release of the draft environmental study of the Spring Creek expansion kicks off a 30-day public comment period. A final decision is expected by late 2019, Lane said.

 Photo: The Spring Creek Mine in Montana is the state's largest coal mine. Photo credit: Cloud Peak Energy.