Black Hills Corp. said that its subsidiaries Black Hills Power and Cheyenne Light, Fuel & Power were issued an air permit by the U.S. Environmental Protection Agency to begin construction of a $237 million, 132 MW natural gas-fired power plant in Wyoming. Black Hills needs the Cheyenne Prairie Generating Station to replace 82 MW of coal-fired generation that will be retired by March 2014 and a 40 MW power supply agreement that is ending in 2014. The Cheyenne Prairie Generating Station will consist of a 37 MW simple-cycle combustion turbine owned by Cheyenne Light and a 95 MW combined cycle combustion turbine to be jointly owned by Black Hills Power (55 MW) and Cheyenne Light (40 MW). Construction is expected to begin in April 2013 and the plant could be ready for commercial operation by late 2014.