Peabody Energy opened the North Antelope Mine in the heart of Wyoming’s Powder River Basin in 1983. The Rochelle mine was opened in 1984. 

North Antelope Rochelle is a surface mine. Draglines and trucks and shovels are used to remove the overburden. Trucks then haul the coal from the three pits to trains for shipment to customers. 

The average grade of the coal shipped from the mine is 8,800 British thermal units per pound (20,000 kJ/kg), 0.2% sulfur, 4.40% ash, and 1.70% sodium (of the ash), making North Antelope Rochelle coal the cleanest in the United States.

According to; Source of photos: internet