Hallador Energy Company, through its subsidiaries, engages in the production of steam coal in the State of Indiana for the electric power generation industry. The company owns the Oaktown Mine 1 and Oaktown Mine 2 underground mines in Oaktown, Indiana; and Ace in the Hole mine located near Clay City, Indiana. It is also involved in gas exploration activities in Indiana. Hallador Energy Company was founded in 1949 and is headquartered in Terre Haute, Indiana.