Kern County is a county spanning the southern end of the California Central Valley. Covering 8,161.42 square miles (21,138.0 km2), it ranges west to the southern slope of the Coast Ranges, and east beyond the southern slope of the eastern Sierra Nevada into the Mojave Desert. The population of Kern County was 839,631 in 2010, making it the eleventh most populous county in the state. Its county seat is Bakersfield. The county's economy is heavily linked to agriculture and to petroleum extraction. There is also strong aviation, space, and military presence, such as Edwards Air Force Base and China Lake Naval Air Weapons Station.