Dominion Resources, Inc., together with its subsidiaries, operates as an integrated gas and electric company in the United States. The company operates in four segments: Dominion Delivery (DD), Dominion Energy (DE), Dominion Generation (DG), and Dominion E&P (DE&P). The DD segment engages in regulated electric and gas distribution, as well as nonregulated retail energy marketing operations, including marketing of gas, electricity, and related products and services. As of December 31, 2006, it served residential, commercial, industrial, and governmental customers with approximately 55,000 miles of electric distribution lines, 27,700 miles of gas distribution pipelines, and 10 underground gas storage fields. The DE segment includes regulated electric transmission, natural gas transmission pipeline, and storage businesses, as well as the Cove Point LNG facility. This segment also engages in gathering and extraction activities; and natural gas production. It owned approximately 6,000 miles of electric transmission lines of 69 kilovolt; and 7,800 miles of gas transmission, gathering, and storage pipelines, as of the above date. The DG segment generates electricity from coal, nuclear, gas, oil, hydro, and purchased power resources with approximately 28,000 megawatts of generation capacity. The DE&P segment engages in the exploration, development, and production of oil and gas in the Gulf of Mexico, West Texas, Mid-Continent, and the Rockies and Appalachia. This segment has approximately 6.5 trillion cubic feet of natural gas and oil reserves. The company was founded in 1909 and is headquartered in Richmond, Virginia.