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 by the Bureau. The riverine reservoir it creates, the Black Canyon Reservoir, has a normal water surface of 1.7 square miles, about twelve miles of shoreline, and an original maximum capacity of 44,700 acre-feet, reduced by siltation to about 31,200 acre-feet. Recreation includes boating and fishing. The installation of a third hydropower generating unit has been funded by Bonneville Power Administration for completion in 2013. 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