Hoover Dam

10. Mike O'Callaghan - Pat Tillman Memorial Bridge

The key component to the Hoover Dam Bypass project, was the first concrete-steel composite arch bridge built in the United States, and incorporates the longest concrete arch in the Western Hemisphere. Opened on October 19, 2010, the 4-lane highway bridge provides a crossing of the Colorado River for U.S. Route 93, linking the U.S. states of Nevada and Arizona 1,600 feet (490 m) downstream from the Hoover Dam. It is located approximately 30 miles (48 km) southeast of Las Vegas, Nevada. At 840 feet (260 m) above the Colorado River, the bridge is the second-highest in the United States, behind Royal Gorge Bridge. Built as part of the Hoover Dam Bypass Project, which successfully finished within budget at a cost of US $240 million, the bridge portion cost US$114 million (2010 prices).