Amador is one of the 58 counties in the state of California. It was created in 1854 from part of Calaveras County. As of the 2010 census the population was 38,091, up from 35,100 in 2000. The county seat is Jackson, and the largest city is Ione.
The county has 604.69 square miles (1,566.1 km2) of area, of which 592.97 sq mi (1,535.8 km2) is land. It is bordered by El Dorado County on the north, Alpine County on the east, Calaveras County on the south, San Joaquin County on the southwest and Sacramento County on the west.