The Kern River Oil Field is a large oil field in Kern County in the San Joaquin Valley of California, north-northeast of Bakersfield in the lower Sierra foothills. According to a California State Historical Marker of the original site in Kern County, "Oil was discovered at 70 feet in 1899, when Tom Means persuaded Roy Elwood and Frank Wiseman, aided by Jonathan, Bert, Jed, and Ken Elwood, George Wiseman, and John Marlowe, to dig here for oil. On June 1, 1899, 400 feet to the north, Horace and Milton McWhorter drilled this region's first commercial well." Yielding a cumulative production of close to 2 billion barrels (320,000,000 m³) of oil by the end of 2006, it is the third largest oil field in California, after the Midway-Sunset Oil Field and the Wilmington Oil Field, and the fifth largest in the United States. Its estimated remaining reserves, as of the end of 2006, were around 476 million barrels (75,700,000 m³), the second largest in the state. It had 9,183 active wells, the second highest in the state.