The colossal Hoover dam that spans the mighty Colorado river amid rugged, rocky terrain with mountains in the background. The clear sky features a few scattered clouds, while roads snake alongside the geological structures. The 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. Constructed between 1931 and 1936. Years after its completion, Hoover dam is still considered an engineering marvel. It is named in honor of President Herbert Hoover, who played a crucial role in its creation.