Alliance Resource Partners, L.P., a diversified natural resource company, engages in the production and marketing of coal to utilities and industrial users in the United States. The company operates through four segments: Illinois Basin Coal Operations, Appalachia Coal Operations, Oil & Gas Royalties, and Coal Royalties. It produces produce bituminous coal from its underground mines sold to electric power generation and the steel production customers. The company operates seven underground mining complexes in Illinois, Indiana, Kentucky, Maryland, Pennsylvania, and West Virginia.