Hoover Dam sits in the Black Canyon of the Colorado River, straddling the border between Nevada and Arizona just a short drive from Las Vegas. Built during the Great Depression by a consortium of contractors known as Six Companies, the dam took about five years to complete, with construction running from 1931 to 1936. Standing 726 feet tall, it was the tallest dam in the world at the time and remains one of the most impressive feats of American engineering.
The dam holds back the Colorado River to form Lake Mead, the largest reservoir in the country by capacity when full. Inside, 17 massive turbines generate hydroelectric power for Nevada, Arizona, and California. You can see the mineral-stained "bathtub ring" along the canyon walls in some of these photos — a reminder of just how much lower the lake has dropped during years of drought in the region. The graceful arch bridge visible downstream is the Mike O'Callaghan-Pat Tillman Memorial Bridge, completed in 2010 to reroute highway traffic that used to cross directly over the dam.
