High Quality Content by WIKIPEDIA articles! The Midway-Sunset Oil Field is a large oil field in Kern County, San Joaquin Valley, California in the United States. Discovered in 1894, and having a cumulative production of close to 3 billion barrels (480,000,000 m3) of oil at the end of 2006, it is the largest oil field in California and the third largest in the United States. As of the end of 2008, its estimated remaining reserves amounted to approximately 532 million barrels (84,600,000 m3) of oil.