The Elk Hills Oil Field (formerly the Naval Petroleum Reserve No. 1) is a large oil field in northwestern Kern County, in the Elk Hills of the San Joaquin Valley, California in the United States, about twenty miles (32 km) west of Bakersfield. Discovered in 1911, and having a cumulative production of close to 1.3 billion barrels (210,000 dam³) of oil at the end of 2006, it is the fifth-largest oil field in California, and the seventh-most productive field in the United States. Its estimated remaining reserves, as of the end of 2006, were around 107 million barrels (17,000 dam³), and it had 2,387 active oil-producing wells.