A haul truck is pictured at a coal seam at a coal mine in the Powder River Basin in Wyoming in this undated handout photo

 
A haul truck is pictured at a coal seam at a coal mine in the Powder River Basin in Wyoming in this undated handout photo
A haul truck is pictured at a coal seam at a coal mine in the Powder River Basin in Wyoming in this undated handout photo obtained by Reuters November 30,2012. REUTERS/National Mining Association/Handout