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 river, except for the "Searchlight" that lingered on as property of the U. S. Reclamation Service until it was sunk in 1916. Steamboats were tried in Glen Canyon, the Green River in Utah and Wyoming and the Grand River, (after 1921 renamed as the upper part of the Colorado River), above its confluence with the Green River in Utah and in Colorado. Unlike the Lower Colorado, the railroads made possible most of this steam navigation on the Upper Colorado, bringing in the boats or their parts and their fuel to the points on the river where they were assembled