San Joaquin County ( ; , meaning "St. Joachim"), officially the County of San Joaquin, is a county in the U.S. state of California. As of the 2020 United States census, the population was 779,233. The county seat is Stockton.

San Joaquin County comprises the entirety of the Stockton metropolitan statistical area, which is adjacent to the San Francisco Bay Area. Located in Calfornia's Central Valley, the county has experienced rapid population growth driven by long-distance commuters priced out of the Bay Area's core. Approximately 10% of San Joaquin County's residents commute 90 or more minutes each way to work, a higher share than any comparable county in the United States. The Altamont Corridor Express, a weekday commuter rail service, connects San Joaquin County with San Jose.

The county is a major winemaking hub, with more acres dedicated to wine grape production than any other county in California.

History San Joaquin County was one of the original counties of California, created in 1850 at the time of statehood.

The county was named after the San Joaquin River, which flows north through it. In the early 19th century, Lieutenant Gabriel Moraga, commanding an expedition in the lower great California Central Valley, gave the name of San Joaquin (meaning Joachim) to the San Joaquin River, which springs from the southern Sierra Nevada. San Joaquin County is the site of the San Joaquin Valley's first permanent residence.

Prior to incorporation in 1850, the area now encompassing San Joaquin County was inhabited by the Yokuts and Miwok native peoples. These communities lived in villages throughout the region, consuming diverse diets that reflected the flora and fauna of the California Delta. Acorns from Valley Oak trees, salmon from the San Joaquin, Mokelumne, Calaveras, and Stanislaus rivers, and Tule Elk were staples of the native diet, which was supplemented with various native berries and plants. The native population of San Joaquin County fell dramatically during a statewide epidemic of malaria in 1828, and a subsequent rebellion of native peoples in the Central Valley, led by Chief Estanislao.

Between 1843 and 1846, during the era when California was a province of independent Mexico, five Mexican land grants were made in what would become San Joaquin County: Rancho Campo de los Franceses, Pescadero (Grimes), Pescadero (Pico), Sanjon de los Moquelumnes, and Thompson. The largest of these grants was the Rancho Campos de los Franceses, secured by Charles Weber and Guillermo Gulnac, which was eventually developed into the city of Stockton.

As the Gold Rush drew miners to the Sierra Nevada, Stockton grew into a major logistical and mercantile hub for the San Joaquin Valley and mother lode, which allowed for the City and County populations to rise significantly between 1850 and 1870. As the state's gold economy waned in the 1870s, San Joaquin County transitioned into a major national center of agriculture, which it remains to this day. Reclamation of the California delta, which began in 1869, strongly benefited this agricultural growth. The importance of agriculture to the region's economy led to the creation of a dynamic industrial engineering sector in Stockton, Lodi, and nearby Rio Vista in the 1880s. Notably, the Sperry Flour Company, Holt Manufacturing Company, the operation of R. G. LeTourneau, Samson Ironworks, and the canning empire of Tillie Lewis were firms of national and international significance. Holt Manufacturing, led by Benjamin Holt, would pioneer the industrial manufacturing and sales of the tractor, while R. G. LeTourneau patented the bulldozer in 1926.

Importance to railroads The Central Pacific Railroad in the 1860s utilized San Joaquin County's exceptionally flat terrain to construct a rail line from Sacramento to Stockton and then southwest through Altamont Pass to the San Francisco Bay. Notably, the Mossdale Bridge crossing the San Joaquin River was the last link on the first transcontinental railroad from the Missouri River to the Pacific Ocean. In 1909, a second railroad, the Western Pacific, utilized the same route through Stockton to reach the Bay Area. In the early 1900s, the Santa Fe Railroad constructed from Bakersfield and Fresno went through Stockton to travel northwards, reaching Oakland. Smaller lines constructed at Stockton were the Tidewater Southern to Modesto and the Central California Traction to Sacramento. Both started as electrically powered. These railroads encouraged the growth of farms, orchards, and ranches in San Joaquin County and adjacent counties.

Tracy tire fire On August 7, 1998, a tire fire ignited at S.F. Royster's Tire Disposal just south of Tracy on South MacArthur Drive, near Linne Rd. The tire dump held over 7 million illegally stored tires and was allowed to burn for more than two years before it was extinguished. Allowing the fire to burn was considered to be a better way to avoid groundwater contamination than putting it out.Rubber Threat: Tracy tire fire highlights old problem. Lodi News-Sentinel. August 18, 1998. However, the cleanup cost $19 million and local groundwater was still discovered to be contaminated.Breitler, Alex. Byproducts from 1998 tire fire found in water, Record. December 20, 2005.

The Corral Fire

On June 1, 2024, the Corral Fire ignited south of Tracy. It was the first major wildfire of 2024. The fire started at Site 300 of the Lawrence Livermore National Laboratory. The fire grew fast, as on the same day, it went from 30 acres at 4:44pm, to 4,940 acres at around 7:50pm. By the end of the day, CAL FIRE Santa Clara Unit was assigned to the wildfire.

The next day, June 2, 2024, two firefighters were injured while the fire reached 12,500 acres. It reached peak size at 6:52 pm, standing at 14,168 acres. Two-hundred households were evacuated. On June 3, 2024 with the fire still at peak size, CAL FIRE assigned 45 engines, 15 water tenders, 16 dozers, 14 hand crews, and 40 other vehicles, totaling 475 personnel. By that evening, one house was destroyed.

On June 6, 2024, the fire was declared 100% contained. In the chaos of those last five days, two firefighters were injured, one structure was destroyed, and costed an estimated $3.5 million (2024 USD) to suppress.

Geography According to the U.S. Census Bureau, the county has a total area of , of which is land and , comprising 2.5%, is water. The county has a very low inland elevation and a very flat drainage basin for the San Joaquin River and its numerous tributaries. With the resulting exceptionally high water table, the county is a marshy and swampy delta with a tendency to flood in the spring with melting snow runoff from the Sierra Nevada Mountains.

The geographical center of San Joaquin County is near Stockton at approximately 37°54'N 121°12'W (37.9,-121.2).

National protected area San Joaquin River National Wildlife Refuge (part)

Demographics

2020 census As of the 2020 census, the county had a population of 779,233. The median age was 35.4 years, 26.4% of residents were under the age of 18, and 13.7% were 65 years of age or older. For every 100 females there were 99.3 males, and for every 100 females age 18 and over there were 97.3 males.

The racial makeup of the county was 34.3% White, 7.7% Black or African American, 1.6% American Indian and Alaska Native, 17.9% Asian, 0.7% Native Hawaiian and Pacific Islander, 23.3% from some other race, and 14.5% from two or more races. Hispanic or Latino residents of any race comprised 41.8% of the population.

92.2% of residents lived in urban areas, while 7.8% lived in rural areas.

There were 241,119 households in the county, of which 41.7% had children under the age of 18 living with them and 25.1% had a female householder with no spouse or partner present. About 19.0% of all households were made up of individuals and 8.7% had someone living alone who was 65 years of age or older.

There were 251,453 housing units, of which 4.1% were vacant. Among occupied housing units, 59.3% were owner-occupied and 40.7% were renter-occupied. The homeowner vacancy rate was 1.1% and the rental vacancy rate was 3.6%.

Racial and ethnic composition

+San Joaquin County, California – Racial and ethnic compositionRace / Ethnicity (NH = Non-Hispanic)Pop 1980Pop 1990Pop 2000Pop 2010 Pop 2020% 1980% 1990% 2000% 2010% 2020White alone (NH)237,233282,766267,002245,919215,53068.30%58.83%47.37%35.88%27.66%Black or African American alone (NH)18,44424,79136,13948,54056,8985.31%5.16%6.41%7.08%7.30%Native American or Alaska Native alone (NH)3,4573,8073,5313,1793,1351.00%0.79%0.63%0.46%0.40%Asian alone (NH)19,88855,77462,12694,547134,6845.73%11.60%11.02%13.80%17.28%Native Hawaiian or Pacific Islander alone (NH)x included in the Asian category in the 1980 Censusx included in the Asian category in the 1990 Census1,6243,2484,9770.29%0.47%0.29%0.47%0.64%Other race alone (NH)1,7558171,2251,3834,1920.51%0.17%0.22%0.20%0.54%Mixed race or Multiracial (NH)x not an option in the 1980 Censusx not an option in the 1990 Census19,87822,14934,092xx3.53%3.23%4.38%Hispanic or Latino (any race)66,565112,673172,073266,341325,72519.16%23.44%30.53%38.86%41.80%Total347,342480,628563,598685,306779,233 100.00%100.00%100.00%100.00%100.00%

2010 census The 2010 United States census reported that San Joaquin County had a population of 685,306. The racial makeup of San Joaquin County was 349,287 (51.0%) White, 51,744 (7.6%) African American, 7,196 (1.1%) Native American, 98,472 (14.4%) Asian, 3,758 (0.5%) Pacific Islander, 131,054 (19.1%) from other races, and 43,795 (6.4%) from two or more races. Hispanic or Latino of any race were 266,341 persons (38.9%). The Filipino-American population at 46,447 comprised 47% of all Asian Americans in San Joaquin County, and as of 1990 have been the largest population of Asian Americans in the county.

Population reported at 2010 United States census San Joaquin County685,306349,28751,7447,19698,4723,758131,05443,795266,341 Escalon7,1325,823308096228232581,928Lathrop18,0237,4101,3002313,9681443,7351,2357,674Lodi62,13442,6625175604,29310511,1642,83322,613Manteca67,09641,8402,8697354,78038411,6484,84025,317Ripon14,29711,392221125599361,2087163,177Stockton291,707108,04435,5483,08662,7161,82260,33220,159117,590Tracy82,92243,7245,95371512,22974713,1736,38130,557 Acampo341169013813624199August8,3903,914224183358203,1105815,897Collierville1,9341,552142149122968518Country Club9,3795,744472159628421,5377973,790Dogtown2,5062,0401523572253116638Farmington2071647160181142French Camp3,3761,67841031163119201631,748Garden Acres10,6485,244233172358403,9086937,338Kennedy3,2545172002325842,1091432,513Lincoln Village4,3812,97115458269135363801,422Linden1,7841,54161025112774385Lockeford3,2332,52610226413413185956Morada3,8282,848472841230263200676Mountain House9,6753,467903453,830716636961,637Peters6725327152006038153Taft Mosswood1,530443192101831617841,099Terminous3813382670131540Thornton1,13155443345144342770Victor293177071907911150Waterloo572450052117718152Woodbridge3,9842,997154620175821361,234 All others not CDPs (combined)70,49648,5262,3527952,81523212,8782,89826,128

2000 As of the census of 2000, there were 563,598 people, 181,629 households, and 134,768 families residing in the county. The population density was . There were 189,160 housing units at an average density of . The racial makeup of the county was 58.1% White, 6.7% Black or African American, 1.1% Native American, 11.4% Asian, 0.4% Pacific Islander, 16.3% from other races, and 6.1% from two or more races. 30.5% of the population were Hispanic or Latino of any race. 9.3% were of German, 5.3% Irish and 5.0% English ancestry according to Census 2000. 66.4% spoke English, 21.3% Spanish, 2.2% Tagalog, 1.8% Mon-Khmer or Cambodian, 1.1% Vietnamese and 1.1% Hmong as their first language.