San Joaquin County, CA

The USDA Economic Research Service Food Access Research Atlas flags 105 of San Joaquin County's 195 census tracts as low-access, covering 336,720 residents of a 779K total population. That translates to a county-wide low food access share of 43.2%, which measures how many people live more than one mile from the nearest supermarket in urban settings or more than ten miles in rural settings. Because California classifies tracts using the same distance thresholds the USDA applies nationwide, San Joaquin County's figure is directly comparable to peer counties and to the state benchmark.

The food desert signal strengthens when distance is stacked with income. In San Joaquin County, 75,840 residents are flagged as low-income and more than one mile from a supermarket (the urban threshold), while 25,280 meet the low-income, ten-mile rural threshold. Those overlapping conditions are the precise combination the USDA uses to designate a food desert tract. Layered context includes a median household income of $82,837, a poverty rate of 12.9%, and SNAP participation covering 36,307 households — roughly 15.3% of the county — drawn from the Census Bureau American Community Survey five-year estimates.

Transportation is the hidden variable behind most food access gaps. About 5.2% of San Joaquin County households report no vehicle available, meaning any measured distance to a supermarket translates into a real trip on foot, by transit, or by asking for a ride. Group quarters residents — 2.3% of the population — are counted separately because their food access patterns follow an institution rather than a household. With more than 30% of San Joaquin County in a low-access area, the county sits well above the national median and warrants closer review of supermarket siting, SNAP outreach, and transit connections.