Arch Coal Inc is a producer of coal. The company sells its coal to power plants, steel mills, and industrial facilities. It operates more than ten active mines in the United States. Its segments include the Powder River Basin division in Wyoming, which consists of the Black Thunder and Coal Creek mines, and the Appalachia segment in West Virginia, Kentucky, Maryland, and Virginia, which consists of the Coal-Mac, Lone Mountain, Mountain Laurel, Beckley, Vindex, Sycamore No. 2, Sentinel, and Leer mines. The majority of the revenue is earned from the sale of coal from the Powder River Basin segment.