About 91 Alpha subsidiary Highland Mining Company employees have been advised of the expected idling of its Superior, North, and Trace Fork surface mines, and a reduction in workforce at its Reylas and Freeze Fork surface mines.

Seven workers with Alpha’s Rum Creek Coal's Anna Branch reclamation unit, working at the affected mines, will also be displaced.

About 25% of the affected workers will continue to perform reclamation work as three of the operations wind down to an idle state.

The mine idlings and workforce reduction are expected to be completed by mid-April.

“These actions are being triggered by persistent weakness in US and overseas coal demand and depressed price levels, along with regulatory pressures contributing to the premature retirement of coal-fired power plants across the nation,” Alpha said in a statement.

“Excess supply of coal worldwide also has contributed to falling coal prices.”

Alpha chairman and CEO Kevin Crutchfield said the company needed to continue to adjust to challenging market conditions.

“We made a short-term decision in November to keep these mines operating as existing coal supply contracts were being fulfilled,” Crutchfield said.

“Unfortunately, despite the hard work of these operations to reduce costs in this unprecedented business climate, prices remain depressed and current coal supply simply exceeds demand.”

The mines that are being idled produced 1.5 million tons of thermal coal in 2014.

“These actions are consistent with steps that we've taken in the past to build a smaller but more sustainable portfolio of mining assets across our operational footprint,” Crutchfield added.

“We are confident that a portion of the displaced miners will be able to fill available positions at other Alpha-affiliated mines.”