Hoover Dam is a concrete arch-gravity dam in the Black Canyon of the Colorado River, on the border between Nevada and Arizona. It was built between 1931 and 1936 during the Great Depression, and dedicated on September 30, 1935 by President Franklin D. Roosevelt.
Thousands of workers built it, and more than 96 lost their lives. The consortium Six Companies, Inc. began construction in early 1931, and the dam was turned over to the federal government on March 1, 1936, more than two years ahead of schedule.
The dam impounds Lake Mead. It is near Boulder City, Nevada, about 30 miles (48 km) southeast of Las Vegas, and about 7 million tourists visit each year.