Alliance Resource Partners is a natural resource company. Co. is a coal producer in the eastern U.S. with underground mining complexes in Illinois, Indiana, Kentucky, Maryland, Pennsylvania, and West Virginia as well as a coal-loading terminal in Indiana on the Ohio River. Co. has four segments: Illinois Basin Coal Operations, which includes its operating mining complexes Gibson County Coal's mining complex; Appalachia Coal Operations, which includes its the Mettiki mining complex, the Tunnel Ridge mining complex and the MC Mining mining complex; Oil and Gas Royalties, which includes oil and gas mineral interests; and Coal Royalties, which includes coal mineral reserves and resources.