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
Steamboats of the Colorado River Steamboats of the Colorado River Steamboats on the Colorado River operated from the river mouth at the Colorado River Delta on the Gulf of California in Mexico, up to the Virgin River on the Lower Colorado River Valley in the Southwestern United States from 1852 until 1909, when the construction of the Laguna Dam was completed. The shallow draft paddle steamers were found to be the most economical way to ship goods between the Pacific Ocean ports and settlements and mines along the lower river, putting in at landings in Sonora state, Baja California Territory, California state, Arizona Territory, New