The Powder River Basin is a geologic region in southeast Montana and northeast Wyoming, about 120 miles (190 km) east to west and 200 miles (320 km) north to south, known for its coal deposits. The region supplies about 40 percent of coal in the United States.
It is the single largest source of coal mined in the United States, and contains one of the largest deposits of coal in the world. Most of the active coal mining in the Powder River Basin actually takes place in drainages of the Cheyenne River. Because of the Powder River Basin, Wyoming has been the top coal-producing state in the United States since 1988. In 2007, the Powder River Basin alone produced 436 million short tons (396 million tonnes) of coal, more than twice the production of second-place West Virginia, and more than the entire Appalachian region.
The BNSF Railway is the second-largest freight railroad network in North America, second to the Union Pacific Railroad, with a network of 32,500 route miles in 28 states and two Canadian provinces.
Headquartered in Fort Worth, Texas, the railroad is a wholly owned subsidiary of Berkshire Hathaway Inc., and employs almost 40,000 people. In 2012, BNSF hauled 2.2 million coal shipments, enough to power one out of every 10 homes in the United States.