Named one of the Top 10 Construction Achievements of the 20th Century, Hoover Dam was the largest of its kind at the time and many years after. Despite the remote location and harsh working conditions, construction begain in 1930 and the dam was completed in less than five years -- two years ahead of schedule -- and well under budget.

The dam is named after America's 31st president, Herbert Hoover, who played a large role in bringing the nearby states into agreement about water allocations, settling a 25-year controversy. The dam has been called Boulder Canyon Dam as well as Boulder Dam, but Hoover Dam was reinstated as the official name by Congress in 1947.

The impressive newly built Hoover Dam bypass bridge, perched 890 feet above the turquoise Colorado River, officially opens to traffic in October, 2010,