FILE - In this Jan. 9, 2014, file photo, rail cars are filled with coal and sprayed with a topper agent to suppress dust at Cloud Peak Energy’s Antelope Mine north of Douglas, Wyo.
FILE - In this Jan. 9, 2014, file photo, rail cars are filled with coal and sprayed with a topper agent to suppress dust at Cloud Peak Energy’s Antelope Mine north of Douglas, Wyo. Ryan Dorgan Casper Star-Tribune
FILE - In this Jan. 9, 2014, file photo, rail cars are filled with coal and sprayed with a topper agent to suppress dust at Cloud Peak Energy’s Antelope Mine north of Douglas, Wyo. Ryan Dorgan Casper Star-Tribune