An image of power generators at Hoover Dam. Caption on image reads: "Interior of powerhouse at Boulder Dam, with six 115,000-H.P generators installed. Service Bureau photo." 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.

Downstream face of Boulder Dam

President Franklin D. Roosevelt stands watch on the left as two trumpeteers start the dedication ceremony for the Boulder Dam Opening of the Spillways.

Hoover (Boulder) Dam, taken from the upstream side of the dam on the Nevada side. May, 1947. The intake towers, Nevada spillway house (in the background, behind the intake towers), and the Nevada spillway are visible. During the years of lobbying leading up to the passage of legislation authorizing the dam in 1928, Hoover Dam was originally referred to "Boulder Dam" or as "Boulder Canyon Dam", even though the proposed site had shifted to Black Canyon. The Boulder Canyon Project Act of 1928 (BCPA) never mentions a proposed name or title for the dam. When Secretary Wilbur spoke at the ceremony starting the building of the railway between Las Vegas and the dam site on September 17, 1930, he named the dam "Hoover Dam", citing a tradition of naming dams after Presidents, though none had been so honored during their terms of office. After Hoover's election defeat in 1932 and the accession of the Roosevelt administration, Secretary Ickes ordered on May 13, 1933 that the dam be referred to as "Boulder Dam". In the following years, the n

A colored postcard showing an artist's representation of Boulder Dam, later known as Hoover Dam, in Black Canyon, with Fortification Mountain lying in background. From this angle, intake towers can be seen sticking out of Lake Mead, along with the U-shaped power house at the base of the dam.

Walkways and towers as part of the structure of the Hoover Dam, seen from below in the reservoir.