BACKSTORY: Named one of the Top 10 Construction Achievements of the 20th Century, Hoover Dam attracts more than a million visitors a year to its Black Canyon location, just minutes outside of Las Vegas. In 1930, construction began on the Hoover Dam, the largest of its kind at the time. Despite the remote location and harsh working conditions, it 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. A National Historic Landmark, Hoover Dam is the highest concrete dam in the Western Hemisphere, standing at more than 725 feet above the Colorado River. With 17 generators producing 4 billion kilowatts of electricity a year, it also is one of the country's largest hydroelectric power facilities. Operation and maintenance of the facility are solely supported by revenue from power sales.