About San Andreas, California
San Andreas is an unincorporated census-designated place and the county seat of Calaveras County, California. The population was 2,783 at the 2010 census, up from 2,615 at the 2000 census. Like most towns in the region, it was originally founded during the California Gold Rush. The town is located on State Route 49 and is registered as California Historical Landmark #252.