Imperial County is located in the Imperial Valley, in California, bordering both Arizona and Mexico. By 2006 the population had risen to 160,201. The county seat is the city of El Centro. The county is the newest and one of the poorest of all of California's counties. The County was formed in 1907 and took its name from Imperial Valley, itself named for the Imperial Land Company. The county has a total area of 4,482 mi², 93% of it is land and 7% of it is water. Two notable geographic features here are the Salton Sea, at 235 feet below sea level, and the Algodones Dunes, one of the largest dune fields in America.