The four-lane Hoover Dam bypass bridge opened to traffic in Nov. 2009 is:
-The highest and longest arched concrete bridge in the Western Hemisphere.
-The second-highest bridge of any kind in the United States and 14th in the world.
-The world's tallest concrete columns of their kind.

It is perched 890 feet above the turquoise Colorado River, wedged between rock cliffs that form Black Canyon, with commanding views of Hoover Dam and Lake Mead.
It is named the Mike O’Callaghan-Pat Tillman Memorial Bridge.

JULY 2011 CHALLENGE: ARCHITECTURE IN BLACK AND WHITE