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
Agriculture in the Southwestern United States any other region of the United States, so it is warmer on average. There are two main physiographic regions which Arizona is a part of. North and east Arizona is part of the Colorado Plateau, and the Basin and Range is in southern and western Arizona. The Colorado Plateau is a flat, elevated land of soft sedimentary rock about 5,000 to 9,000 feet above sea level. Rivers cut deep canyons and gorges into the plateau, the largest of which is the Grand Canyon of the Colorado River, which is in the northwest corner of Arizona. There are also scattered mountains