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
Course of the Colorado River Course of the Colorado River The Colorado River is a major river of the western United States and northwest Mexico in North America. Its headwaters are in the Rocky Mountains where La Poudre Pass Lake is its source. Located in north central Colorado it flows southwest through the Colorado Plateau country of western Colorado, southeastern Utah and northwestern Arizona where it flows through the Grand Canyon. It turns south near Las Vegas, Nevada, forming the Arizona–Nevada border in Lake Mead and the Arizona–California border a few miles below Davis Dam between Laughlin, Nevada and Needles, California California before entering Mexico