The 1,440-mile-long Colorado River passes through parts of seven states, several Indian reservations and the Republic of Mexico. California is entitled to 4.4 million acre-feet of water annually from river. Most of that water irrigates crops in the Palo Verde, Imperial and Coachella valleys, located in the southeastern corner of the state, but the Colorado also is a vital source of water for urban southern California. Urban supplies are distributed by the Metropolitan Water District of Southern California through its Colorado River Aqueduct. MWD is a water wholesale agency that supplies water to water districts that serve 18 million customers in Los Angeles, Orange, San Diego, Riverside, San Bernardino and Ventura counties.