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 of the Gunnison National Park Black Canyon of the Gunnison National Park Black Canyon of the Gunnison National Park is an American national park located in western Colorado and managed by the National Park Service. There are two primary entrances to the park: the south rim entrance is located east of Montrose, while the north rim entrance is south of Crawford and is closed in the winter. The park contains of the long Black Canyon of the Gunnison River. The national park itself contains the deepest and most dramatic section of the canyon, but the canyon continues upstream into Curecanti National Recreation Area and downstream