Black Canyon of the Colorado Black Canyon of the Colorado The Black Canyon of the Colorado is the canyon on the Colorado River where Hoover Dam was built. The canyon is located on the Colorado River at the state line between Nevada and Arizona. The western wall of the gorge is in the El Dorado Mountains, and the eastern wall is in the Black Mountains of Arizona. The canyon formed about 15 million years ago during the Miocene Basin and Range uplift. Black Canyon gets its name from the black volcanic rocks that are found throughout the area. Just south of the Hoover Dam on
Black Canyon Diversion Dam Black Canyon Diversion Dam Black Canyon Diversion Dam (National ID # ID00282) is a dam in Gem County, Idaho. The concrete dam was originally completed in 1924, then re-constructed between 1951 and 1955, by the United States Bureau of Reclamation. Its structure has a height of 183 feet, and a length of 1902 feet at its crest. It impounds the Payette River for the diversion of water into the Black Canyon and North Side Main irrigation canals, and the generation of about 2 megawatts of hydroelectric power, part of the Bureau's larger Boise Project. The dam is owned and operated