View from Hoover Dam of the 2010 Mike O'Callaghan Pat Tillman Memorial Bridge past the massive dam. Like the dam the bridge, which primarily carries U.S. highway 93 vehicular traffic, straddles the border between Arizona and Nevada in the Black Canyon of the Colorado River. The bridge, which became a favorite photography spot for tourists, is named after O'Callaghan, a decorated Korean War veteran and onetime Nevada governor, and Tillman, who had played football for the Arizona State University and the Arizona Cardinals but relinquished his multimillion-dollar career in the National Football League to enlist as an infantryman in the U.S. Army. Tillman was killed by friendly fire in Afghanistan in 2004. Photo by Carol Highsmith.