Arch Coal, Inc is a diversified coal company engaged in coal production, marketing and supply of cleaner-burning, low-sulfur thermal and metallurgical coal to power generators and steel manufacturers over five continents. The Company's business segments include the Powder River Basin (PRB), with operations in Wyoming; the Appalachia (APP), with operations in West Virginia, Kentucky, Maryland and Virginia. Its domestic reserve base consists of more than 5 billion tons of metallurgical and thermal coal reserves and represents 14% of America’s coal supply from active mining complexes in Wyoming, Colorado, Illinois, West Virginia, Kentucky, Virginia and Maryland. Arch is performing surface mining in Black Thunder, Coal Creek Mine, Sentinel and Vindex, and underground mining is performed in West Elk Mine, Viper Mine, Beckley Complex, Lone Mountain, and Leer Mining Complex. Both surface and underground mining is performed in Coal-Mac, Cumberland River and Mountain Laurel mining complexes.