Colorado River-Hoover Dam. Diagram of Boulder Dam in construction from book: Boulder Dam of the Great Southwest, by Ralph B. Simmons, 1936. Image taken January 4, 1940. Site Name: Hoover Dam (dam)
An image showing a bird's eye view of Hoover Dam from the Arizona side, featuring intake towers. Caption on bottom right of image reads: "Upstream face of Boulder Dam showing intake towers and Arizona observation point. [Copyright] BDSB." Boulder Dam was officially renamed Hoover Dam in 1947.