FILE - In this April 2007, file photo, a shovel prepares to dump a load of coal into a 320-ton truck at the Black Thunder Mine in Wright, Wyo. Government data shows U.S. coal exports reached their highest level in two decades last year as strong overseas demand offered an outlet for a fuel that?s been falling from favor at home. The U.S. Department of Energy data analyzed by The Associated Press reveals that coal exports topped 107 million tons in 2011. That?s the highest level since 1991 and more than double the export volume from just six years ago. (AP Photo/Matthew Brown, File)