There are 11 US Post Offices in Yuba County serving a total of 72,213 residents equating to 6,565 residents per post office. It's estimated that approximately 115,260 packages are handled across the 11 county post offices annually. Yuba County is a county located in the U.S. state of California. As of the 2010 census, the population was 72,155. The county seat is Marysville. Yuba County is included in the Yuba City, CA Metropolitan Statistical Area, which is also included in the Sacramento-Roseville, CA Combined Statistical Area. The county is located in California's Central Valley along the Feather River."