Hoover Dam Hoover Dam Hoover Dam is a concrete arch-gravity dam in the Black Canyon of the Colorado River, on the border between the U.S. states of Nevada and Arizona. It was constructed between 1931 and 1936 during the Great Depression and was dedicated on September 30, 1935, by President Franklin D. Roosevelt. Its construction was the result of a massive effort involving thousands of workers, and cost over one hundred lives. Originally known as Boulder Dam from 1933, it was officially renamed Hoover Dam, for President Herbert Hoover, by a joint resolution of Congress in 1947. Since about 1900, the Black
Black Canyon Diversion Dam Black Canyon Diversion Dam Black Canyon Diversion Dam (National ID # ID00282) is a dam in Gem County, Idaho. The concrete dam was originally completed in 1924, then re-constructed between 1951 and 1955, by the United States Bureau of Reclamation. Its structure has a height of 183 feet, and a length of 1902 feet at its crest. It impounds the Payette River for the diversion of water into the Black Canyon and North Side Main irrigation canals, and the generation of about 2 megawatts of hydroelectric power, part of the Bureau's larger Boise Project. The dam is owned and operated