San Joaquin County, California: Size, Population, and Key Facts

By the Numbers

Geographic Context

Located in the Central Valley, the county is roughly the size of Rhode Island. The San Joaquin River and California Delta waterways define its western edge. Major cities: Stockton (county seat), Tracy, Manteca, Lodi, Lathrop.

Economic Profile

• Agriculture: Top producer of cherries, asparagus, tomatoes, almonds, walnuts, grapes.
• Logistics: I-5, CA-99, BNSF/UP rail, Port of Stockton — major inland distribution hub.
• Energy: Natural gas fields, growing solar.

Water Area Significance

The 56 sq mi of water (3.9% of total) includes Delta channels, reservoirs (New Hogan, Camanche), and the river itself—critical for irrigation, recreation, and ecosystem health.