Historical Facts of California Counties

California County records can vary vastly from county to county both in quality and quantity. Some happen to have been carefully maintained while others have been substantially misused and overlooked. A certain amount of California records have simply disappeared. For genealogists carrying out research in California there’s no effective substitute to have an on-site search of county court house records. For Definitions of all court terms see the Genealogy Encyclopedia.

On January 4, 1850, the California constitutional committee recommended the formation of 18 counties. They were Benicia, Butte, Fremont, Los Angeles, Mariposa, Monterey, Mount Diablo, Oro, Redding, Sacramento, San Diego, San Francisco, San Joaquin, San Jose, San Luis Obispo, Santa Barbara, Sonoma, and Sutter.

California Counties

California is divided into 58  counties. Each county serves as the local level of government within its borders. 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 within incorporated cities. California State Government is located in Sacramento.

Some counties encompass land settled in the eighteenth century; their records pre-date county formation. Land transactions and vital records recorded in the county are at the county recorder’s office. The county clerk general has probate books and files from the county’s superior court, civil court records, and naturalizations. Divorces may be in either place, depending on how filed.

The links in the table below link to county and city government offices and is limited to government-maintained websites. If you know of a California county that has an official government web site but is not linked, or if the link is in error, please contact us so we may edit our database.

County Date Formed Parent County County Seat
Alameda March 25, 1853 Contra Costa and Santa Clara Counties Oakland
Alpine March 16, 1864 Amador, El Dorado, Calaveras, Mono and Tuolumne Counties Markleeville
Amador May 11, 1854 Calaveras County Jackson
Butte February 18, 1850 Original County Oroville
Calaveras February 18, 1850 Original County San Andreas
Colusa February 18, 1850 Original County Colusa
Contra Costa February 18, 1850 Original County Martinez
Del Norte March 2, 1857 Klamath County Crescent City
El Dorado February 18, 1850 Original County Placerville
Fresno April 19, 1856 Mariposa, Merced and Tulare Counties Fresno
Glenn March 11, 1891 Colusa County Willows
Humboldt May 12, 1853 Trinity County Eureka
Imperial August 6, 1907 San Diego County El Centro
Inyo March 22, 1866 Mono and Tulare Counties Independence
Kern April 2, 1866 Los Angeles and Tulare Counties Bakersfield
Kings March 22, 1893 Tulare County Hanford
Lake May 20, 1861 Napa County Lakeport
Lassen April 1, 1864 Plumas and Shasta Counties, and now defunct Lake County, Nevada Susanville
Los Angeles February 18, 1850 Original County Los Angeles
Madera March 11, 1893 Mariposa County Madera
Marin February 18, 1850 Original County San Rafael
Mariposa February 18, 1850 Original County Mariposa
Mendocino February 18, 1850 Original County Ukiah
Merced April 19, 1855 Mariposa County Merced
Modoc April 19, 1855 Siskiyou County Alturas
Mono April 24, 1861 Calaveras, Fresno and Mariposa Counties Bridgeport
Monterey February 18, 1850 Original County Salinas
Napa February 18, 1850 Original County Napa
Nevada April 25, 1851 Yuba County Nevada City
Orange March 11, 1889 Los Angeles County Santa Ana
Placer  April 25, 1851 Sutter and Yuba Counties Auburn
Plumas March 18, 1854 Butte County Quincy
Riverside March 11, 1893 San Bernardino and San Diego Counties Riverside
Sacramento February 18, 1850 Original County Sacramento
San Benito February 12, 1874 Monterey County Hollister
San Bernardino April 26, 1853 Los Angeles County San Bernardino
San Diego February 18, 1850 Original County San Diego
San Francisco February 18, 1850 Original County San Francisco
San Joaquin February 18, 1850 Original County Stockton
San Luis Obispo February 18, 1850 Original County San Luis Obispo
San Mateo April 19, 1856 San Francisco and Santa Cruz Counties Redwood City
Santa Barbara February 18, 1850 Original County Santa Barbara
Santa Clara February 18, 1850 Original County San Jose
Santa Cruz February 18, 1850 Original County Santa Cruz
Shasta February 18, 1850 Original County Redding
Sierra April 16, 1852 Yuba County Downieville
Siskiyou March 22, 1852 Shasta and Klamath Counties Yreka
Solano February 18, 1850 Original County Fairfield
Sonoma February 18, 1850 Original County Santa Rosa
Stanislaus April 1, 1854 Tuolumne County Modesto
Sutter February 18, 1850 Original County Yuba City
Tehama April 9, 1856 Butte, Colusa and Shasta Counties Red Bluff
Trinity February 18, 1850 Original County Weaverville
Tulare April 20, 1852 Mariposa County Visalia
Tuolumne February 18, 1850 Original County Sonora
Ventura March 22, 1872 Santa Barbara County Ventura
Yolo February 18, 1850 Original County Woodland
Yuba February 18, 1850 Original County Marysville


Interactive Map of California Counties Formation

(California maps made with the use AniMap Plus 3.0 & with the Permission of the Goldbug Company)

California Extinct Counties

California seems to have counties that no longer exist. They were created by the state, provincial, or territorial authorities. A lot of these counties were established and disbanded in the Nineteenth century; county boundaries have adjusted very little since Nineteen hundred in the great most of states. These counties really should be investigated when doing genealogy research. Pay attention where the courthouse records went to if the county was eliminated or combined with some other county.

  • Branciforte County was one of the original 27 counties adopted by statutes of 1850, but soon after that the legislature changed the name to Santa Cruz County.
  • Coloma County was a county proposed by a committee of the California Constitutional Convention. Before the statute was adopted, the legislature changed the name to El Dorado County.
  • Coso County was approved by the State Legislature which designated territory in Mono County and Tulare County to be in the new county with the county seat at Bend City. Coso County, however, was never organized. In 1866 substantially the same territory was created as Inyo County.
  • Fremont County was a county proposed by a committee of the California Constitutional Convention. Before the statute was adopted, the legislature changed the name to Yola County and later changed the name to Yolo County.
  • Klamath County was created on 1851 from the northern half of Trinity County. In 1857 Klamath County lost significant territory to the newly formed Del Norte County. In 1875 Klamath County was abolished and its territory was divided between Humboldt County and Siskiyou County. Territory which at one time was in Klamath County is now in Del Norte County, Humboldt County, Siskiyou County, and Trinity County.
  • Mount Diablo County was a county proposed by a committee of the California Constitutional Convention. Before the statute was adopted, the legislature changed the name to Contra Costa County.
  • Oro County was a county proposed by a committee of the California Constitutional Convention. Before the statute was adopted, the legislature changed the name to Tuolumne County.
  • Pautah County was created on 1852, an act to be effective when the United States Congress ceded to the State of California the territory described, in what is now the State of Nevada. The County seat was to be Carsonville. California never acquired the territory and the act creating the county was repealed in 1859.
  • Redding County was a county proposed by a committee of the California Constitutional Convention. Before the statute was adopted, the legislature changed the name to Shasta County.

California Counties with Burned Courthouses

The damage to California courthouses considerably has a bearing on genealogists in just about every way. Not only are these types of historic buildings torn from all of our lifetimes, so are the archives they stored: marriage, wills, probate, land records, among others. Once destroyed they’re destroyed permanently. Despite the fact that they have already been placed on mircofilm, computers and film burn as well. The most tragic aspect of this is the reason why almost all of our courthouses are destroyed as a result of arsonist. Although, not all the records were damaged or lost. Many California counties have experienced a loss of records due to courthouse fires, floods, and theft.

  • Amador Co. Courthouse – Courthouse destroyed by fire in 1862. Some records were destroyed.
  • Del Norte Co. Courthouse- The courthouse was destroyed by fire in 1948. Some early records were destroyed.
  • El Dorado Co. Courthouse – A fire in 1910 & 1920 destroyed most courthouse records. For probate records prior to 1951, write County Nuseum, 100 Placerville
    Drive, Placerville, California 95667; for probate after 1951, write to Judicial Section, 495 Main Street, Placerville,
    California 95667.
  • Inyo Co. Courthouse – was destroyed by an earthquake March 26, 1872. On June 30, 1886 a fire broke out in a vacant building in Independence and destroyed thirty-eight buildings. Although the county records and most of the furniture were saved, the courthouse was one of the buildings destroyed.
  • Lake Co. Courthouse – courthouse in Lakeport burned down in 1867. All earlier records were destroyed.
  • Madera Co. Courthouse – A fire on Christmas Eve 1906 destroyed the upper floors and tower.
  • Nevada Co. Courthouse – The first courthouse was damaged by fire in 1856. Fire again damaged the courthouse in 1863.
  • Sacramento Co. Courthouse- The first courthouse, built in 1851, became the Capitol in 1854 and was destroyed in a fire that same year.
  • San Francisco Co. Courthouse – Courthouse and all records were destroyed in the great earthquake and fire of 1906.
  • Santa Clara Co. Courthouse – May 18, 1931, a fire quickly spread through the courthouse, causing extensive damage.
  • Shasta Co. Courthouse – All records were destroyed in the great fire of June 14th, 1853
  • Sierra Co. Courthouse – Fire in 1947 destroyed courthouse. No records were lost
  • Sonoma Co. Courthouse – was destroyed in the 1906 earthquake. Minor record Loss.
  • Sutter Co. Courthouse – The Courthhouse was destroyed by fire in 1871. A second and larger courthouse, completed in 1873, was also set fire.