Hoover Dam, previously known as Boulder Dam is named after Herbert Hoover, who played an important role in its construction, first as the Secretary of Commerce, and then later, as the President of the United States. Construction began in 1931, and was completed in 1936. Hoover Dam is a concrete arch-gravity in the Black Canyon of the Colorado River, or the border between the U.S. States of Arizona and Nevada. When completed in 1936, it was both the world's largest hydroelectric power generating station and the world's 38th largest electric generating station. This huge dam was built to provide irrigation water flow, for flood control, and for hydroelectric power generation.
In the wake of the September 11 2001,terrorists attacks, there are significant security concerns. Because of the attack, the Hoover Dam Bypass was expedited. Traffic across Hoover Dam is presently restricted. Some types of vehicles are inspected prior to crossing the dam while semi-trailer trucks, buses carrying luggage, and enclosed-box trucks over 40 ft. long are not allowed in the dam at all. That traffic was diverted south of Colorado river bridge at Laughlin, Nevada. To provide much more highway capacity, and better safety, the new Hoover Dam Bypass is scheduled to be completed in 2010 and it will divert the U.S. traffic 1,500 ft. downstream from the dam. Once the bypass is completed, through traffic will no longer be allowed across Hoover Dam.
