Which river does Nevada’s Hoover Dam hold back?

Nevada’s Hoover Dam holds back the Colorado River.

The dam stands in Black Canyon on the border between the U.S. states of Arizona and Nevada. It was built during the Great Depression, with construction running from 1931 to 1936. The resulting reservoir is Lake Mead, named for Elwood Mead, who supervised the project as commissioner of the U.S. Bureau of Reclamation.

Hoover Dam was initially called Boulder Dam, reflecting the earlier name used for the project and nearby construction settlement. Congress officially changed the name to Hoover Dam in 1947, honoring former president Herbert Hoover.

The dam produces hydroelectric power, regulates water flow, and supplies water to communities and farms in the southwestern United States. Lake Mead is not a separate river: it is the reservoir created when the Colorado River was impounded behind the dam.