Machinery for construction of Boulder Dam, 1931-1936

A comparison of an image of Hoover Dam's upstream face in February 1935 to an image taken later that year, after the waters of Lake Mead had risen. The captions read "February 1935- Boulder Dam today." Boulder Dam was officially re-named Hoover Dam in 1947.

An image showing a bird's eye view of Hoover Dam and vehicles on its crest from the Nevada side. The name was officially changed from Boulder Dam to Hoover Dam in 1947.

This series of photographs documents the historic water overflow at Hoover Dam as seen from the Arizona side of the dam. Taken in August of 1983, this overflow marked the first time the spillways were used during a flood. After initially being filled, the spillways were tested once in August of 1941.

An aerial view of Hoover Dam with Fortification Mountain in distance.

Photograph taken by John McCreary of the side wall of the Hoover Dam under construction, January 1934.

Lowering 180-ton section of Penstock Pipe, Boulder Dam, 1931-1936