Hoover Dam, once known as Boulder Dam, is a concrete arch-gravity dam in the Black Canyon of the Colorado River, on the border between the U.S. states of Arizona and Nevada. When completed in 1936, it was both the world's largest hydroelectric power generating station and the world's largest concrete structure.It is currently the world's 38th-largest hydroelectric generating station.


Mike O'Callaghan – Pat Tillman Memorial Bridge known as the Hoover Dam Bypass during planning and early construction, provides a bridge connecting roads for a new route across the Colorado River for U.S. Route 93. The project links the U.S. states of Nevada and Arizona by spanning the Colorado River 1,600 ft (490 m) downstream from the Hoover Dam. The bridge is expected to be open to traffic in November 2010.

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