Black and white image of a crowd of people gathered together for the Boulder Junction, a ceremony celebrating the beginning of work on Boulder Canyon Project and the beginning of construction on a Union Pacific Railroad from Boulder Junction (Bracken Junction) to the dam site. Note: Boulder Dam was officially renamed Hoover Dam in 1947.

Black and white image of the Colorado River Board, a group comprised to review the Bureau of Reclamation's design of Hoover Dam (note: Boulder Dam was officially renamed Hoover Dam in 1947). From left to right: William L. Siebert; Elwood Mead; Warren J. Mead; Charles Berkey; Daniel W. Mead; and Robert Ridgway.

Colorado River-Hoover Dam. Dam and powerhouse construction from book: Boulder Dam of the Great Southwest by Ralph B. Simmons' 1936. Inscription reads: "Below the massive wedge of concrete showing the power house rising against the hard rock walls of Black Canyon." Site Name: Hoover Dam (dam)

Newsletter issued by the Las Vegas Rotary Club

Newsletter issued by the Las Vegas Rotary Club

Black and white image of the construction phase of the Boulder Canyon Project, also known as Hoover Dam. Excavation for the Hoover Dam construction substation by the Nevada-California Power Company is visible. Note: Boulder Dam was officially renamed Hoover Dam in 1947.