An image of the upstream face of Boulder Dam. Freshly built, the dam had low water levels as it continued to be filled with water. Boulder Dam was officially renamed Hoover Dam in 1947.

An image of a lone car on a bridge located over the Arizona spillway near Boulder Dam. Boulder Dam was officially renamed Hoover Dam in 1947.

A view of the interior of Boulder Dam, as seen from a visitor viewpoint platform; a man leans against the railing, looking down at power generators below. Boulder Dam was officially renamed Hoover Dam in 1947.

The view of a penstock tunnel located within the interior of Boulder Dam. Visitors of the dam stand above a bridge overlooking the tunnel. Boulder Dam was officially renamed Hoover Dam in 1947.

An image of President Franklin D. Roosevelt giving a speech to a crowd at the Boulder Dam dedication ceremony (officially renamed Hoover Dam in 1947).

An image of Boulder City Rotary Club members sitting at a table at a luncheon held near Boulder Dam (officially renamed Hoover Dam in 1947).

An image of Rotary Club members attending a lunch near Boulde Dam (officially renamed Hoover Dam in 1947). Three unidentified men stand beside each other eating food and wearing chef hats.