Occidental Petroleum announced in 2009 that it had made a major discovery of oil and natural gas in Kern County, calling it the largest onshore California oil and gas discovery in 35 years. Although Occidental declined to divulge the location, state records show that Occidental has been drilling wells to depths of at the northwest end of Elk Hills Field, between Elk Hills and Railroad Gap Field. Occidental estimated the new find to contain 150 million barrels of oil equivalent (BOE), of which about one-third is oil.