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
Steamboats of the Colorado River the Colorado Steam Navigation Company between Yuma and Needles. By the end of 1905 all the steamboats, "Cochan", "St. Vallier" and "Searchlight", were withdrawn down river to Yuma. Their places were taken by smaller gasoline powered boats, until they were in turn replaced by trucks. The remaining steamboats worked on irrigation projects on the lower part of the river and on repairing the 1904-1907 breach in the Alamo Canal, that directed the Colorado River into the Salton Sink and created the Salton Sea before it was repaired. The last project, the construction of the Laguna Dam ended steam navigation on