The first European to see the area wasGabriel Moraga in 1806.
The county was named after the Estanislao River, which in turn was named in honor ofEstanislao, a mission-educatedrenegadeNative American chief who led a band of Native Americans in a series of battles againstMexican troops until finally being defeated byGeneralMariano Vallejo in 1826. Estanislao was his baptismal name, the Spanish name version afterSaint Stanislaus the Martyr.
Stanislaus County was formed from part ofTuolumne County in 1854. The county seat was first situated at Adamsville, then moved to Empire in November, La Grange in December, and Knights Ferry in 1862, and was ultimately fixed at the present location in Modesto in 1871.[16]
As the price of housing has increased in the San Francisco Bay Area, many people who work in the southern reaches of the Bay Area have opted for the longer commute and moved to Stanislaus County for the relativelyaffordable housing.
According to theU.S. Census Bureau, the county has a total area of 1,515 square miles (3,920 km2), of which 20 square miles (52 km2) (1.3%) are covered by water.[17]
Stanislaus County has historically been divided socially and economically by the north-flowing San Joaquin River, which provided a natural barrier to trade and travel for much of the county's history. Isolated from the main rail corridors through the county and theirrigation projects that generated much of the region's economic prosperity, the part of Stanislaus County west of the river (known to locals as the "West Side" of the county) has largely remained rural and economically dependent on agricultural activities. Because of its proximity toInterstate 5 and theCalifornia Aqueduct, some towns within this area, includingPatterson andNewman, have experienced tremendous growth and are being transformed intobedroom communities forcommuters from the nearby San Francisco Bay Area, while others (includingWestley andCrows Landing) have been almost entirely overlooked by development and remain tiny farming communities.
A number or rare andendangered species are found in Stanislaus County. The beaked clarkia, (Clarkia rostrata), is listed as a candidate for the federal endangered species list. It has only been found inblue oak-gray pine associations in thefoothills of theSierra Nevada, ahabitat that occurs at moderately high elevations. Colusa grass, (Neostapfsia colusana) is listed as endangered by the state. It is restricted tovernal pools.[18]
Modesto City-County Airport has previously had a number of scheduled passenger flights. Currently, its main air traffic is general aviation. Other (general aviation) airports around the county includeOakdale Airport, Patterson Airport, and Turlock Airpark.
Stanislaus County, California – Racial and ethnic composition Note: the US Census treats Hispanic/Latino as an ethnic category. This table excludes Latinos from the racial categories and assigns them to a separate category. Hispanics/Latinos may be of any race.
The2010 United States census reported that Stanislaus County had a population of 514,453. The racial makeup of Stanislaus County was 337,342 (65.6%) White, 14,721 (2.9%) African American, 5,902 (1.1%) Native American, 26,090 (5.1%) Asian (1.5% Indian, 1.1% Filipino, 0.7% Cambodian, 0.5% Chinese, 0.3% Vietnamese, 0.3% Laotian, 0.1% Japanese, 0.1% Korean, 0.1% Cambodian), 3,401 (0.7%) Pacific Islander, 99,210 (19.3%) from other races, and 27,787 (5.4%) from two or more races. Hispanics or Latinos of any race were 215,658 persons (41.9%); 37.6% of Stanislaus County is Mexican, 0.6% Puerto Rican, 0.5% Salvadoran, 0.2% Nicaraguan, and 0.2% Guatemalan.[38]
(Note - the US Census Bureau says "this system treats race and ethnicity as separate and independent categories. This means that within the federal system, everyone is classified as both a member of one of the four race groups and also as either Hispanic or non-Hispanic." Consequently, there are a total of 8 race-ethnicity categories (e.g., White-Hispanic, White-non-Hispanic, Black-Hispanic, Black non-Hispanic, etc.). That, in turn, means that the total Hispanic population is made up of each of the four groups, thus the separate distinction for Hispanic and non-Hispanic.)[39]
As of thecensus[40] of 2000, 446,997 people, 145,146 households, and 109,585 families were residing in the county. Thepopulation density was 299 people per square mile (115 people/km2). The 150,807 housing units had an average density of 101 units per square mile (39 units/km2). The racial/ethnic makeup of the county was 69.3% White, 2.6% Black, 4.2% Asian, 1.3% Native American, 0.3% Pacific Islander, 16.8% from other races, and 5.4% from two or more races. About 31.7% of the population were Hispanic or Latino of any race; 8.4% were ofGerman, 6.3%English, 6.0%American, 5.5%Irish, and 5.1%Portuguese ancestry according toCensus 2000. About 67.8% spokeEnglish, 23.7%Spanish, 1.5%Syriac, and 1.3%Portuguese as their first languages.
Of the 145,146 households, 41.2% had children under 18 living with them, 56.0% were married couples living together, 13.7% had a female householder with no husband present, and 24.5% were not families. About 19.4% of all households were made up of individuals, and 7.9% had someone living alone who was 65 or older. The average household size was 3.03, and the average family size was 3.47.
In the county, the age distribution was 31.1% under 18, 9.8% from 18 to 24, 29.0% from 25 to 44, 19.5% from 45 to 64, and 10.4% who were 65 or older. The median age was 32 years. For every 100 females, there were 96.8 males. For every 100 females 18 and over, there were 93.4 males.
The median income for a household in the county was $40,101, and for a family was $44,703. Males had a median income of $36,969 versus $26,595 for females. Theper capita income for the county was $16,913. About 12.3% of families and 16.0% of the population were below thepoverty line, including 20.5% of those under 18 and 8.8% of those 65 or over.
Thegovernment of Stanislaus County is defined and authorized under theCalifornia Constitution andlaw as ageneral law county. The county government provides countywide services such as elections and voter registration, law enforcement, jails, vital records, property records, tax collection, public health, and social services. In addition, the county serves as the local government for all unincorporated areas.
The county government is composed of the elected five-member board of supervisors, several other elected offices including thesheriff-coroner, district attorney, tax assessor, auditor-controller, treasurer-tax collector, and clerk-recorder, and numerous county departments and entities under the supervision of the chief executive officer. As of January 2025, the members of the Stanislaus County Board of Supervisors were:[45]
The Stanislaus County Sheriff provides court protection, jail administration, and coroner services for the entire county. It provides patrol and detective services for the unincorporated areas of the county. The sheriff also provides law-enforcement services by contract to the municipalities of Riverbank, Patterson, Waterford, Salida, and Hughson. These municipalities fund police coverage as specified in the respective sheriff's contract with each city.[46]
Just like neighboringMerced County, Stanislaus is considered a bellwether county in presidential elections. The last major-party nominee to gain over 60% of the vote wasLyndon B. Johnson in1964. Furthermore, in1960, Stanislaus County was one of the most bellwether counties in terms of the popular vote, voting 0.02% more Democratic than the national average. It has voted for the winning candidate for president in every election since1972, except in2016 when it voted forHillary Clinton instead ofDonald Trump. In2024,Donald Trump won the county in a decisive victory, continuing the county's bellwether county status.
Trump's win in Stanislaus County made it one of ten counties in California to flip fromBiden toTrump, as well as making Stanislaus one of six counties to vote for the Republican presidential candidate for the first time in 20 years sinceGeorge W. Bush in2004. The last Democrat to win a majority in the county wasJimmy Carter in1976, althoughBarack Obama won aplurality in2008 and2012, as didBill Clinton in both1992 and1996, and as Biden did in2020.
United States presidential election results for Stanislaus County, California[48]
^John Torrey, Paul Awosika et al.,Expanded initial study, Boulder Creek subdivision, Stanislaus County, Earth Metrics, Report 7999: California State Clearinghouse, Sacramento, November 1989.
^abcdefghijklmnopqU.S. Census Bureau. American Community Survey, 2011 American Community Survey 5-Year Estimates, Table B02001.U.S. Census website. Retrieved October 26, 2013.
^abU.S. Census Bureau. American Community Survey, 2011 American Community Survey 5-Year Estimates, Table B03003.U.S. Census website. Retrieved October 26, 2013.
^abU.S. Census Bureau. American Community Survey, 2011 American Community Survey 5-Year Estimates, Table B19301.U.S. Census website. Retrieved October 21, 2013.
^abU.S. Census Bureau. American Community Survey, 2011 American Community Survey 5-Year Estimates, Table B19013.U.S. Census website. Retrieved October 21, 2013.
^abU.S. Census Bureau. American Community Survey, 2011 American Community Survey 5-Year Estimates, Table B19113.U.S. Census website. Retrieved October 21, 2013.
^abU.S. Census Bureau. American Community Survey, 2011 American Community Survey 5-Year Estimates.U.S. Census website. Retrieved October 21, 2013.
^U.S. Census Bureau. American Community Survey, 2011 American Community Survey 5-Year Estimates, Table B01003.U.S. Census website. Retrieved October 21, 2013.
Sol P. Elias,Stories of Stanislaus: A Collection of Stories on the History and Achievement of Stanislaus County. Modesto, CA: Sol P. Elias, 1924.
A Memorial and Biographical History of the Counties of Merced, Stanislaus, Calaveras, Tuolumne and Mariposa, California. Chicago: Lewis Publishing Co., 1892.