San Joaquin County ( ; , meaning "St. Joachim"), officially the County of San Joaquin, is located 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 Stockton–Lodi–Tracy metropolitan statistical area within the regional San Jose–San Francisco–Oakland combined statistical area. The county is located in Northern California's Central Valley just east of the very highly populated nine-county San Francisco Bay Area region. It is separated from the East Bay partly by the Diablo Range, through which there is road and rail access to Alameda County via the Altamont Pass, and partly by the Sacramento-San Joaquin Delta, through which there are links to Contra Costa County via road, rail, and shipping, and to Solano County via road. One of the smaller counties by area in California, it has a high population density and is growing rapidly due to overflow from the Bay Area.
The City of San Joaquin, despite sharing its name with the county, is located in Fresno County.
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. However, the cleanup cost $19 million and local groundwater was still discovered to be contaminated.
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)