Founded 1907, Imperial County is a county located in the Imperial Valley, in the far southeast of the U.S. state of California, and borders both Arizona and Mexico. It is part of the 'El Centro, California Metropolitan Statistical Area' which encompasses all of Imperial County. The population as of 2000 was 142,361. The county seat is the city of El Centro. The county took its name from Imperial Valley, itself named for the Imperial Land Company, a subsidiary of the California Development Company, which at the turn of the 20th century had reclaimed the southern portion of the Colorado desert for agriculture. Geography: According to the U.S. Census Bureau, the county has a total area of 11,608 km² (4,482 mi²). 10,812 km² (4,175 mi²) of it is land and 795 km² (307 mi²) of it (6.85%) is water.

The Colorado River forms the county's eastern boundary. Two notable geographic features are found in the county, the Salton Sea, at 235 feet below sea level, and the Algodones Dunes, one of the largest dune fields in America.The Chocolate Mountains are located east of the Salton Sea, and extend in a northwest-southeast direction for approximately 60 miles.