San Joaquin County, California

San Joaquin County is a county in the U.S. state of California. As of the 2010 census, the population was 685,306. The county seat is Stockton.San Joaquin County comprises the Stockton-Lodi, CA Metropolitan Statistical Area, which is also included in the more inclusive San Jose-San Francisco-Oakland, CA Combined Statistical Area. The county is located in Northern California's Central Valley, just east of the less extensive nine-county San Francisco Bay Area region.The City of San Joaquin, despite sharing its name with the county, is located in Fresno County.HistorySan Joaquin County was one of the original United States counties of California, created in 1850 at the time of statehood.The county was named for the San Joaquin River which runs 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.