Knowledge Base Wiki

The state of California has 58 counties. Counties are responsible for all elections, property-tax collection, maintenance of public records such as deeds, and local-level courts within their borders, as well as providing law enforcement (through the county sheriff and sheriff's deputies) to areas that are not in cities.

California's United States Postal Service code is CA and its FIPS code is 06.

County	FIPS code[1]	County seat[2]	Established[2]	Formed from	Meaning of name[3]	Population (2020)[4]	Area[2]	Map
Alameda County	001	Oakland	1853	Contra Costa and Santa Clara	Spanish for "avenue shaded by trees" or "cottonwood grove."	1,682,353	738 sq mi (1,911 km2)
Alpine County	003	Markleeville	1864	Amador, El Dorado, Calaveras, Mono and Tuolumne	Location high in the Sierra Nevada.	1,204	739 sq mi (1,914 km2)
Amador County	005	Jackson	1854	Calaveras	Jose Maria Amador (1794–1883), a soldier, rancher, and miner who, along with several Native Americans, made a successful gold mining camp near present-day Amador City in 1848.	40,474	606 sq mi (1,570 km2)
Butte County	007	Oroville	1850	Original	Sutter Buttes, mistakenly thought to be in the county during the county's establishment.	211,632	1,640 sq mi (4,248 km2)
Calaveras County	009	San Andreas	1850	Original	Calaveras River; calaveras is Spanish for "skulls".	45,292	1,020 sq mi (2,642 km2)
Colusa County	011	Colusa	1850	Original	Rancho Colus land grant from Mexico.	21,839	1,151 sq mi (2,981 km2)
Contra Costa County	013	Martinez	1850	Original	Spanish for "opposite coast", from its location across San Francisco Bay from San Francisco.	1,165,927	720 sq mi (1,865 km2)
Del Norte County	015	Crescent City	1857	Klamath	Spanish for "northern", from its far northern location.	27,743	1,008 sq mi (2,611 km2)
El Dorado County	017	Placerville	1850	Original	El Dorado, a mythical city of gold, owing to the area's importance in the California Gold Rush.	191,185	1,712 sq mi (4,434 km2)
Fresno County	019	Fresno	1856	Mariposa, Merced and Tulare	Fresno Creek; fresno is Spanish for "ash tree."	1,008,654	5,963 sq mi (15,444 km2)
Glenn County	021	Willows	1891	Colusa	Dr. Hugh J. Glenn, a California businessman and politician.	28,917	1,315 sq mi (3,406 km2)
Humboldt County	023	Eureka	1853	Trinity	Humboldt Bay, named after Alexander von Humboldt, a German naturalist and explorer.	136,463	3,573 sq mi (9,254 km2)
Imperial County	025	El Centro	1907	San Diego	Imperial Valley, named for the Imperial Land Company.	179,702	4,175 sq mi (10,813 km2)
Inyo County	027	Independence	1866	Mono and Tulare	Disputed original; early settlers believed Inyo to be the native name for area mountains, but this term may be the name of a Mono Indian leader	19,016	10,192 sq mi (26,397 km2)
Kern County	029	Bakersfield	1866	Los Angeles and Tulare	Kern River, named for Edward Kern, cartographer for John C. Fremont's 1845 expedition.	909,235	8,142 sq mi (21,088 km2)
Kings County	031	Hanford	1893	Tulare	Kings River, original Spanish name Rio de los Santos Reyes ("River of the Holy Kings").	152,486	1,390 sq mi (3,600 km2)
Lake County	033	Lakeport	1861	Napa	Clear Lake	68,163	1,258 sq mi (3,258 km2)
Lassen County	035	Susanville	1864	Plumas and Shasta, and now defunct Lake County, Nevada	Peter Lassen, a Danish naturalist and explorer.	32,730	4,558 sq mi (11,805 km2)
Los Angeles County	037	Los Angeles	1850	Original	Spanish for "The Angels", abbreviated from El Pueblo de Nuestra Señora la Reina de los Angeles del Río de Porciúncula (The Village of Our Lady, the Queen of the Angels of the river of Porziuncola).	10,014,009	4,060 sq mi (10,515 km2)
Madera County	039	Madera	1893	Mariposa	Spanish for "wood", in reference to the forested area of the landscape	156,255	2,138 sq mi (5,537 km2)
Marin County	041	San Rafael	1850	Original	Disputed, but could be a corrupted abbreviation of Bahía de Nuestra Señora del Rosario la Marina, the Spanish name for area headlands along San Francisco Bay.	262,231	520 sq mi (1,347 km2)
Mariposa County	043	Mariposa	1850	Original	Spanish for "butterfly".	17,131	1,451 sq mi (3,758 km2)
Mendocino County	045	Ukiah	1850	Original	Antonio de Mendoza, first viceroy of New Spain.	91,601	3,509 sq mi (9,088 km2)
Merced County	047	Merced	1855	Mariposa	Merced River; original Spanish name El Río de Nuestra Señora de la Merced ("River of Our Lady of Mercy").	281,202	1,929 sq mi (4,996 km2)
Modoc County	049	Alturas	1874	Siskiyou	The Modoc people	8,700	3,944 sq mi (10,215 km2)
Mono County	051	Bridgeport	1861	Calaveras, Fresno and Mariposa	Mono Lake; name derived from Monachi, a Yokut name for native peoples of the Sierra Nevada.	13,195	3,044 sq mi (7,884 km2)
Monterey County	053	Salinas	1850	Original	Monterey Bay, Spanish portmanteau of monte ("hill") and rey ("king").	439,035	3,322 sq mi (8,604 km2)
Napa County	055	Napa	1850	Original	Disputed origin; possibly derived from the Patwin word napo, meaning home.	138,019	754 sq mi (1,953 km2)
Nevada County	057	Nevada City	1851	Yuba	Spanish for "snow-covered", referencing the area's high elevation	102,241	958 sq mi (2,481 km2)
Orange County	059	Santa Ana	1889	Los Angeles	The orange, which was widely grown in the area at the time the county was established.	3,186,989	790 sq mi (2,046 km2)
Placer County	061	Auburn	1851	Sutter and Yuba	Spanish term for gravel deposits that contain gold; references the California Gold Rush, which was centered in the area.	404,739	1,503 sq mi (3,893 km2)
Plumas County	063	Quincy	1854	Butte	Feather River; Spanish name El Rio de las Plumas.	19,790	2,554 sq mi (6,615 km2)
Riverside County	065	Riverside	1893	San Bernardino and San Diego	The city of Riverside, named for its location on the Santa Ana River.	2,418,185	7,208 sq mi (18,669 km2)
Sacramento County	067	Sacramento	1850	Original	Sacramento River, named for the Santisimo Sacramento (Spanish for "Most Holy Sacrament").	1,585,055	966 sq mi (2,502 km2)
San Benito County	069	Hollister	1874	Monterey	Saint Benedict (San Benedicto in Spanish; Benito is the diminutive of Benedicto).	64,209	1,389 sq mi (3,597 km2)
San Bernardino County	071	San Bernardino	1853	Los Angeles	City of San Bernardino, named for Saint Bernardino of Siena (San Bernardino de Siena in Spanish)	2,181,654	20,062 sq mi (51,960 km2)
San Diego County	073	San Diego	1850	Original	Spanish for Saint Didacus	3,298,634	4,204 sq mi (10,888 km2)
San Francisco County	075	San Francisco	1850	Original	Spanish for Saint Francis.	873,965	47 sq mi (122 km2)
San Joaquin County	077	Stockton	1850	Original	Spanish for Saint Joachim.	779,233	1,399 sq mi (3,623 km2)
San Luis Obispo County	079	San Luis Obispo	1850	Original	Spanish for Saint Louis, the Bishop.	282,424	3,304 sq mi (8,557 km2)
San Mateo County	081	Redwood City	1856	San Francisco and Santa Cruz	Spanish for Saint Matthew.	764,442	449 sq mi (1,163 km2)
Santa Barbara County	083	Santa Barbara	1850	Original	Spanish for Saint Barbara.	448,229	2,738 sq mi (7,091 km2)
Santa Clara County	085	San Jose	1850	Original	Spanish for Saint Clare.	1,936,259	1,291 sq mi (3,344 km2)
Santa Cruz County	087	Santa Cruz	1850	Original	Mission Santa Cruz; Spanish for holy cross	270,861	446 sq mi (1,155 km2)
Shasta County	089	Redding	1850	Original	Mount Shasta	182,155	3,786 sq mi (9,806 km2)
Sierra County	091	Downieville	1852	Yuba	Spanish for "mountain range", referencing the area's topography	3,236	953 sq mi (2,468 km2)
Siskiyou County	093	Yreka	1852	Shasta and Klamath	Siskiyou Mountains; meaning of Siskiyou is disputed.	44,076	6,287 sq mi (16,283 km2)
Solano County	095	Fairfield	1850	Original	Chief Solano of the Suisunes	453,491	828 sq mi (2,145 km2)
Sonoma County	097	Santa Rosa	1850	Original	Disputed origin; possibly a Pomo term meaning "valley of the moon", which references a native legend about spiritual activity in the area.	488,863	1,576 sq mi (4,082 km2)
Stanislaus County	099	Modesto	1854	Tuolumne	Stanislaus River, named for Estanislao.	552,878	1,495 sq mi (3,872 km2)
Sutter County	101	Yuba City	1850	Original	John Sutter, a Swiss pioneer of California associated with the California Gold Rush.	99,633	603 sq mi (1,562 km2)
Tehama County	103	Red Bluff	1856	Butte, Colusa and Shasta	The Tehama people, a local Native American tribe.	65,829	2,951 sq mi (7,643 km2)
Trinity County	105	Weaverville	1850	Original	The Trinity River, named for the town of Trinidad (Spanish for "Trinity").	16,112	3,179 sq mi (8,234 km2)
Tulare County	107	Visalia	1852	Mariposa	Tulare Lake	473,117	4,824 sq mi (12,494 km2)
Tuolumne County	109	Sonora	1850	Original	Disputed origin; possibly a corruption of the native term talmalamne, which means cluster of stone wigwams and references local cave dwelling tribes.	55,620	2,236 sq mi (5,791 km2)
Ventura County	111	Ventura	1872	Santa Barbara	Abbreviation of San Buenaventura, Spanish for St. Bonaventure.	843,843	1,846 sq mi (4,781 km2)
Yolo County	113	Woodland	1850	Original	The Yolan people, a local Native American tribe.	216,403	1,012 sq mi (2,621 km2)
Yuba County	115	Marysville	1850	Original	The local Maidu native peoples who lived on the banks of what is now known as the Feather & Yuba Rivers - or by Gabriel Moraga who used the Spanish name for wild grapes growing abundantly at the river's edge.	81,575	630 sq mi (1,632 km2)

• Klamath County was formed in 1851 from the northern half of Trinity County. Part of the county's territory went to Del Norte County in 1857, and in 1874 the rest was split between Humboldt and Siskiyou counties.
• Pautah County was formed in 1852 out of land which, the state of California thought, was to be given to it by the United States Congress from land in what is now the state of Nevada. In 1859 when the cession never occurred, the California State Legislature did not make the county.