The 726-foot-high arch-gravity dam stretches 1,244 feet across the Black Canyon and was built over five years starting in 1931, helping provide water and hydroelectrical power to the West.

High Scalers drill into the canyon wall 500 feet above the Colorado River in Black Canyon at the Hoover Dam site. April 1, 1932. Bureau of Reclamation. Even under the best of conditions ...

The 726-foot-high arch-gravity dam stretches 1,244 feet across the Black Canyon and was built over five years starting in 1931, helping provide water and hydroelectrical power to the West.