Black and white image of crowds waiting to visit the Hoover Dam power plant on Memorial Day in 1937. Many people are holding tickets ready for the guide to collect. The roof of the cashier's booth is visible beyond the awning. Note: Boulder Dam was officially renamed Hoover Dam in 1947.

Black and white image of the Arizona-side generator room at Hoover Dam, as seen from the balcony at elevation 705. The 40,000 kilowatt ampere generator installed in unit 48 is visible in the background. Note: Boulder Dam was officially renamed Hoover Dam in 1947.

Black and white image of Hoover Dam. A rare view of Hoover Dam against a cloud pattern in a desert sky that is usually clear. The world-famous dam, completed by the Bureau of Reclamation, conquered the Colorado River for the first time in history. The dam, spanning the river between Nevada and Arizona, provides all of Reclamation's multipurpose benefits: flood protection, river control, water storage and conservation for irrigation; municipal and industrial uses; generation of low-cost hydroelectric energy; enhancement of navigation; recreation; and fish and wildlife protection.

Photograph of Dr. Thomas White, Dr. Donald Baepler, and Dr. Juanita White holding a rare engraving of President Lincoln stored in Special Collections, UNLV Library, 1970s.

Black and white image with the following printed description: View showing Senator Wm. F. Knowland, left, Mrs. R.A. Taft and Senator Robert A. Taft during a recent visit to world famous Hoover Dam.

Black and white image of General Dwight D. Eisenhower (prior to becoming President) and Hoover Dam's Director of Power, Louis R. Douglass, talking while on the ramp of the dam's powerhouse.

Black and white aerial image of several high scalers at work at the Hoover Dam construction site, specifically in the location for the Arizona-side intake towers. Note: Boulder Dam was officially renamed Hoover Dam in 1947.