Black Canyon of the Colorado

Black Canyon of the Colorado is the canyon on the Colorado River in which Hoover Dam was built, on the state line between Nevada and Arizona. Its western wall lies in the El Dorado Mountains and its eastern wall in the Black Mountains of Arizona. The canyon formed about 15 million years ago, during Basin and Range uplift in the Miocene, and takes its name from the black volcanic rock found throughout the area. Sauna Cave, south of the dam on the Nevada side, was drilled by miners working on Hoover Dam during its construction; calcium carbonate crystals line its walls, and a hot spring at its end raises the temperature inside to 120 °F. Boy Scout Canyon, which branches off south of the dam, carries water warmed from a geothermal source, and several large hot springs rise on the Arizona bank.

Where it is

Black Canyon of the Colorado is a canyon near Lake Mead National Recreation Area, in Mohave County. It is one of the canyons in this database, and appears in the statewide ranking of Arizona attractions.

How this ranking was reached

No official visitor count is published for Black Canyon of the Colorado, so its score rests on public interest and tourism significance, and is capped below the level a measured attraction can reach. That is why the medium confidence above is not higher. The weighting is explained in full on the methodology page, and every axis is broken out under Facts and sources at the foot of this page.

Note on the data: No official visitor count is published for this attraction.

Sources

• Public interest: Wikimedia pageviews (en.wikipedia, human traffic), 2024
• Coordinates and designations: Wikidata(opens in a new tab)
• County: U.S. Census geography via FCC Area API, resolved from coordinates

Record last verified 2026-08-12.