Black and white image of several prominent figures, in front of a crowd outdoors. From left to right: Governor Balzar of Nevada; Carl Gray, President of Union Pacific Railroad Company; Ray Lyman Wilbur, Secretary of the Interior; Governor of Colorado (possibly Edwin C. Johnson). Gray is handing Lyman the first spike to be driven for the spur line to Boulder Dam. Note: Boulder Dam was officially renamed Hoover Dam in 1947.
Black and white image of several men, including Frank Crowe, Superintendent of Construction, at the Hoover Dam construction site. Note: Boulder Dam was officially renamed Hoover Dam in 1947.
Black and white aerial view of Black Canyon at Hoover Dam construction site. There are four visible bridges going over the Colorado River. Note: Boulder Dam was officially renamed Hoover Dam in 1947.
Black and white aerial view of Black Canyon at Hoover Dam construction site. There are four visible bridges going over the Colorado River. Note: Boulder Dam was officially renamed Hoover Dam in 1947.
Black and white image of the Hoover Dam tunnel construction site. There are four visible bridges over the Colorado River. Note: Boulder Dam was officially renamed Hoover Dam in 1947.