The county has a large agricultural base and is a significant producer of oil, natural gas, hydro-electric power, wind-turbine power, and geothermal power. As of 2004, Kern remains California's top oil-producing county, with over 85% of the state's 43,000 active oil wells. The county accounts for one-tenth of overall U.S. oil production, and three of the five largest U.S. oil fields are in Kern County. Kern is also noted for its mineral wealth, including gold, borate, and kernite. The largest open pit mine in California, which mines borax, is at Boron in Kern County.
Department of Defense facilities in Kern County include Edwards Air Force Base and China Lake Naval Air Weapons Station. The Mojave Spaceport, operated by the county government, is also in Kern County.
The American Lung Association ranked Kern County as the most ozone-polluted county in the nation in 2006.
According to the census of 2000, there were 661,645 people, 208,652 households, and 156,489 families residing in the county. The population density was 81 people per square mile (31/km²). There were 231,564 housing units at an average density of 28 per square mile (11/km²). The racial makeup of the county was 61.60% White, 6.02% Black or African American, 3.37% Asian, 1.51% Native American, 0.15% Pacific Islander, 23.22% from other races, and 4.14% from two or more races. 38.39% of the population were Hispanic or Latino of any race. 8.4% were of German, 7.2% American and 5.7% Irish ancestry according to Census 2000. 66.8% spoke English, 29.1% Spanish and 1.0% Tagalog as their first language.
There were 208,652 households out of which 42.2% had children under the age of 18 living with them, 54.6% were married couples living together, 14.5% had a female householder with no husband present, and 25.0% were non-families. 20.3% of all households were made up of individuals and 7.8% had someone living alone who was 65 years of age or older. The average household size was 3.03 and the average family size was 3.50.
In the county the population was spread out with 31.9% under the age of 18, 10.2% from 18 to 24, 29.80% from 25 to 44, 18.7% from 45 to 64, and 9.4% who were 65 years of age or older. The median age was 31 years. For every 100 females there were 105.3 males. For every 100 females age 18 and over, there were 105.3 males.
The median income for a household in the county was $35,446, and the median income for a family was $39,403. Males had a median income of $38,097 versus $25,876 for females. The per capita income for the county was $15,760. About 16.8% of families and 20.8% of the population were below the poverty line, including 27.8% of those under age 18 and 10.5% of those age 65 or over.
The center of population of California is located in Kern County, in the town of Buttonwillow [6].
Kern County is home to over 200,000 Mexican Americans, while the county is a major concentration of migrant laborers arrived in seasonal harvests, mostly from Mexico, Central America and the Philippines, while the Delano area is home to 20,000 Filipino Americans and a sizable Indian American population is in the Arvin area, mainly children and grandchildren of migrant labor families.
There are an estimated 50,000 Cherokee Indians, whose families came to the county from their historic range in Oklahoma and the southeastern US during the 1930s dust bowl migrations of displaced White American and African American farmers from the Great Plains, that as a result brought a uniquely Midwestern/Western country feel to a west coast county, and Bakersfield is referred to as "Nashville West" for its subvariety of Country music developed by these transplants in California since the 1940s. A large share of local residents are 2nd or 3rd generation Okies proud of their families' struggle to work hard to re-established themselves, and they typically lived in Arvin, Buttonwillow, Lamont, Lost Hills, Maricopa, Oildale, Rosedale, Shafter, Taft/Ford city, Tullahassee Wasco and Weedpatch.
Other large ethnic communities in the county are Armenians, Chinese, Germans, Irish, Italian, Japanese, Swedes, Arabs of either Lebanese or Syrian descent, Spanish includes a large Basque community from northern Spain, and Southeast Asians (Cambodia, Laos and Vietnam) mostly arrived after the Vietnam War of the 1970s.
After being informed that gay couples could not be denied marriage licenses in light of the legalization of same-sex marriage, the county announced a halt to all wedding ceremonies, but will issue marriage licenses as required by law. Officials claimed that there would not be enough resources to accommodate ceremonies for both straight and gay couples. Clerks in other counties have called this rationale "...poorly disguised discrimination against gay and lesbian couples."