Hoover Dam the change, stating, "I didn't know Hoover was that small a man to take credit for something he had nothing to do with." Hoover Dam was recognized as a National Civil Engineering Landmark in 1984. It was listed on the National Register of Historic Places in 1981, and was designated a National Historic Landmark in 1985, cited for its engineering innovations. Other sources 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
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