History of California 1900–present conduit and siphons. Average annual throughput is . Davis Dam is located on the Colorado River about downstream from Hoover Dam. Davis Dam stretches across the border between Arizona and Nevada and impounds the Colorado River to form Lake Mohave. The United States Bureau of Reclamation owns and operates the dam, which was completed in 1951. Davis Dam is a zoned earth fill dam with a concrete spillway, in length at the crest, and high. The earth fill dam begins on the Nevada side, but it does not extend to the Arizona side. Instead, there is an inlet formed by
Colorado River Colorado River basin. Below the dam the river passes under the Mike O'Callaghan–Pat Tillman Memorial Bridge – which at nearly above the water is the highest concrete arch bridge in the Western Hemisphere – and then turns due south towards Mexico, defining the Arizona–Nevada and Arizona–California borders. After leaving the confines of the Black Canyon, the river emerges from the Colorado Plateau into the Lower Colorado River Valley (LCRV), a desert region dependent on irrigation agriculture and tourism and also home to several major Indian reservations. The river widens here to a broad, moderately deep waterway averaging wide and reaching