 Hoover Dam <unk> Lake Mead , the largest reservoir in the United States by volume . The dam is located near Boulder City , Nevada , a municipality originally constructed for workers on the construction project , about 30 mi ( 48 km ) southeast of Las Vegas , Nevada . The dam 's generators provide power for public and private utilities in Nevada , Arizona , and California . Hoover Dam is a major tourist attraction ; nearly a million people tour the dam each year . The heavily travelled U.S. 93 ran along the dam 's crest until October 2010 , when the Hoover Dam Bypass opened . 
