Hallador Energy Company, through its subsidiaries, engages in the mining, production, and sale of steam coal for the electric power generation industry in the United States. The company holds interests in the Carlisle underground coal mine located near the town of Carlisle, Indiana; the Ace in the Hole mine located near Clay City, Indiana; the Oaktown 1 underground mine located in Knox County, Indiana; the Oaktown 2 mine/War Eagle reserve located in Knox County, Indiana and Lawrence County, Illinois; and the Bulldog underground mine located in Vermillion County, Illinois. It is also involved in oil and gas exploration activities in Michigan and Indiana. In addition, the company operates a multi-commodity truck/barge terminal located on the Indiana bank of the Ohio River. Hallador Energy Company is based in Denver, Colorado.