An image showing an aerial view of people looking at one of the Hoover Dam spillways. Automobiles travel over a concrete bridge. Note: Boulder Dam was officially renamed Hoover Dam in 1947.
Black and white image of diversion tunnel #2 on the Nevada side of Hoover Dam. This image shows the groundwork for the tunnel. Note: Boulder Dam was officially renamed Hoover Dam in 1947.
Postcard showing the site in Black Canyon where Hoover Dam was originally meant to be built. The name evolved from "Black Canyon Dam" to "Boulder Dam" and was officially named Hoover Dam in the late 1940s. Note on front of post card: "Looking upstream Colorado river Black Canyon Dam Site"; Handwritten note and diagram on back of photo: "Hold this to light and you can get some idea of dimensions of dam."