Bakersfield is the county seat of Kern County, California, in the United States. As of the 2000 census, the city population was 247,057. The city's economy thrives on agriculture, petroleum extraction, and refining. It is one of the fastest growing of the larger cities of the United States. As of 2006 the population is estimated to be around 312,000 within the city limits, and around 451,800 including unincorporated areas, according to local municipal sources. It is California's third largest inland city after Fresno and Sacramento. Top producing area crops include cotton, carrots, table grapes, almonds, pistachios, citrus, wheat, garlic, and potatoes. Local oil fields include the prolific 100-year old Kern River field, the Midway-Sunset field, the former Naval Petroleum Reserve at Elk Hills, the Kern Front field, and the Belridge field.