Lake Mead is the largest reservoir in the United States. It is located on the Colorado River about 30 miles (48 km) southeast of Las Vegas, Nevada, in the states of Nevada and Arizona. Formed by water impounded by Hoover Dam, it extends 110 mi (180 km) behind the dam, holding approximately 28.5 million acre feet (35 km³) of water. The water held in Lake Mead is released to communities in Southern California[1] and Nevada, via aqueducts.