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 by the Bureau. The riverine reservoir it creates, the Black Canyon Reservoir, has a normal water surface of 1.7 square miles, about twelve miles of shoreline, and an original maximum capacity of 44,700 acre-feet, reduced by siltation to about 31,200 acre-feet. Recreation includes boating and fishing. The installation of a third hydropower generating unit has been funded by Bonneville Power Administration for completion in 2013. 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