America’s second-highest bridge now reroutes traffic from the top of the dam.

America’s second-highest bridge now reroutes traffic from the top of the dam.

Since the 1930s, U.S. Route 93 ran right along the top of the dam; however, the two-lane highway was hazardous and had grown increasingly congested over the years. In an effort to remedy these problems, construction began on a dam bypass bridge in 2005. Completed five years later, the Mike O’Callaghan-Pat Tillman Memorial Bridge measures 1,905 feet long and soars nearly 900 feet above the Colorado River, making it the longest single-span concrete arch bridge in the Western Hemisphere as well as the second-highest bridge of any type in America. The structure, which cost $114 million, is named for Donal Neil “Mike” O’Callaghan, a Korean War veteran and two-term Nevada governor during the 1970s, and Pat Tillman, who gave up a professional football career with the Arizona Cardinals to enlist in the Army in 2002; he died in Afghanistan in 2004.