Hoover Dam

Hoover Dam

The Hoover Dam was created to control flooding, provide irrigation water and supply much needed electricity to the southwest area of the United States. It is named after our 31st President, Herbert Hoover.


In 1928, after many years of research, Congress approved a project to begin construction of a dam on the Colordao River. The Hoover Dam project was the largest project of its time. It is located along the border of Arizona and Nevada. Lake Mead was created after the Colorado River was allowed to flow back to the Hoover Dam. Originally, the dam was called Boulder Dam, but in 1947 a bill was passed to officially rename it to honor President Hoover.

photo by: Tomás Del Coro ©

A company called Six Companies won the bid to begin construction on the Dam. Working lights were invented to be used at night, so 24 hour shifts could work around the clock. Over 20,000 workers were used during the construction of the dam. Sadly 96 workers perished during construction.

Four large diversion tunnels were cut into the canyon wall to divert the Colorado River around the construction site. Interlocking blocks and concrete were used to construct the dam. The main construction on the dam started in 1931 and was completed 2 years ahead of schedule in 1935. The Hoover Dam was dedicated by President Franklin D. Roosevelt on September 30, 1935.

Originally, on top of the Hoover Dam is a two lane road serving as the Colorado River U.S. Route 93 crossing. In the wake of September 11, 2001, a four lane bypass called the Mike O’Callaghan – Pat Tillman Memorial Bridge was opened on October 19, 2010 to divert traffic around the Hoover Dam. It is located a mere 1500 feet downstream from the Hoover Dam, which provides beautiful views of the dam. Due to safety concerns, after the bypass opened traffic was no longer permitted to cross the Hoover Dam and only tourists are allowed to cross.

The Bureau of Reclamation started offering tours in 1937. Today, the Hoover Dam attracts over 1,000,000 tourists a year.


The Hoover Dam stretches 726 feet high into the air. The base of the dam is 660 feet thick, while the top is 45 feet thick. The Hoover Dam is filled with 3.25 million cubic yards of concrete. That’s enough to pave a road from San Francisco to New York City 16 feet wide and 8 feet thick.

photo by: Peretz Partensky ©

Original plans called for the installation of 16 electrical generators to be used, but 2 smaller generators were used on the Arizona side in place of one large generator, resulting in 17 total generators. The average electrical output between 1947 and 2008 was approximately 4.2 billion kilowatt-hours. In 1984, the dam generated 10,348,020,500 kilowatt-hours and the lowest capacity was recorded in 1956 at 2,648,224,700 kilowatt-hours.

photo by: Renee Grayson ©

quick facts & Figures

Construction Start: 1931

Construction Ended: 1935

Traffic no longer allowed

Height: 726′

Top Width: 45′

Bottom Width: 660′

Total Concreate: 3.25 Million Cubic Yards

Total Generators: 17

Annual Tourism: 1,000,000