Hoover Dam

About Hoover Dam

A concrete arch-gravity dam in Black Canyon. The largest concrete structure on Earth when finished. Its base is 660 feet thick and the crest 726 feet above bedrock. Enough concrete was poured to pave a sidewalk across America. Built during the Depression and finished 2 years early. Its reservoir, Lake Mead, is the largest in the United States. Over 100 workers died during construction.