Hoover Dam and Lake Mead, spanning the Arizona-Nevada state line, are located in the Black Canyon of the Colorado River in Mohave County, Arizona. Mohave County is in the northwest corner of Arizona. The dam is about 35 miles southeast of Las Vegas, Nevada.

The dam is a concrete thick-arch structure, 726.4 feet high and 1,244 feet long. The dam contains 3.25 million cubic yards of concrete; total concrete in the dam and appurtenant works is 4.4 million cubic yards.

The 726-foot high Hoover Dam began filling in 1935. It is the tallest dam in the Western Hemisphere. Originally called Boulder Dam, it was later named for Herbert Hoover because of his long involvement in the project, from his days as Secretary of Commerce to his tenure as 31st president.

No other politician is more responsible for the successful completion of Hoover Dam than Herbert Hoover.

Anson Smith of Kingman, Arizona was an early supporter of building the dam.

Lake Mead is the reservoir created by the dam. The electrical power provided by Hoover Dam goes to Southern California, 56%, Arizona, 19%, and Nevada, which gets 25% of the allocation.

US 93 did pass over the Colorado River via the top of Hoover Dam, which provided the only crossing point for hundreds of miles. A new bridge by-pass has been built which will help with traffic between Phoenix and Las Vegas.