CNX Gas Corporation engages in the exploration, development, production, and gathering of natural gas primarily in the Appalachian and Illinois basins, the United States. CNX Gas Corporation primarily develops coalbed methane (CBM), as well as conventional marcellus and other shale gas. CNX Gas Corporation holds rights associated with CBM for 4.5 billion tons of proved coal reserves in northern Appalachia, central Appalachia, the Illinois Basin, and other western basins. As of December 31, 2009, CNX Gas had 1.9 trillion cubic feet equivalent of net proved reserves. CNX Gas Corporation is headquartered in Canonsburg, Pennsylvania. CNX Gas Corporation is a subsidiary of CONSOL Energy Inc.