FILE - This Oct. 2, 2012 file photo shows The Hoover Dam and Mike O'Callaghan-Pat Tillman Memorial Bridge from the heliport in Boulder City, Nev. The Depression-era engineering marvel that harnessed ... more 
FILE - This Oct. 2, 2012 file photo shows The Hoover Dam and Mike O'Callaghan-Pat Tillman Memorial Bridge from the heliport in Boulder City, Nev. The Depression-era engineering marvel that harnessed the Colorado River and still supplies massive amounts of power to the Southwest remains one of the most popular stops for the Vegas tourist. (AP Photo/Pablo Martinez Monsivais, file) less 
1 / 30
Associated Press | Photo By Pablo Martinez Monsivais, file
Thu, Oct 18, 2012 11:46 AM EDT