Photographer's notes: "A view of Hoover Dam and Lake Mead from the bridge's pedestrian walkway. Before the bridge's construction, such a view would only have been possible in a helicopter. July 29, 2010." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge

Photographer's notes: "With the bridge complete and open, the bridge, dam and lake now share the Black Canyon. January 14, 2011. Note: This is the uncropped version of this photograph. I chose to crop out the horizon for use in the book and exhibition." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge

Photographer's notes: "Evening view of the Arizona arch segment. Temporary pylons supported cable stays, which in turn supported the arch segments during their construction." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge

Photographer's notes: "From the air, the structural and geographic relationships between the bridge and dam are revealed." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge

Photographer's notes: "Nevada side bridge construction showing the old highway and hairpin turn, April 28, 2009." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge

Photographer's notes: "Aerial view of the bridge's shadow against the face of the dam, January 14, 2011." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge

Photographer's notes: "Upstream view of the complete and open bridge at dusk, January 12, 2011." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge