Sierra County Post Offices

356 Main St
Alleghany, California 95910

15318 Cleveland Ave
Camptonville, California 95922

301 Main St
Downieville, California 95936

22 Post Office Spur
Goodyears Bar, California 95944

500 Main St
Loyalton, California 96118

131 County Rd
Calpine, California 96124

215 Main St
Sierra City, California 96125

306 Lincoln St
Sierraville, California 96126

Sierra County

There are 8 US Post Offices in Sierra County serving a total of 3,597 residents equating to 450 residents per post office. It's estimated that approximately 5,741 packages are handled across the 8 county post offices annually. Sierra County is a county located in the U.S. state of California. As of the 2010 census, the population was 3,240 making it the second-least populous county in California. The county seat is Downieville, and the only incorporated city is Loyalton. The county is located in the Sierra Nevada, northeast of Sacramento on the border with Nevada.