Riley Natural Gas Company is a subsidiary of the Petroleum Development Corporation, which acquired the company in 1996. The company markets natural gas for its parent company and other oil and gas producers in the Appalachian basin. It markets the natural gas to end users, utilities and other marketing companies. The Petroleum Development Corporation is a producer of oil and natural gas. It drills and operates wells in the Rocky Mountain area and the Appalachian and Michigan basins. Established in 1987, Riley Natural Gas Company is located in Bridgeport, W. Va.