Photographer's notes: "Aerial view of bridge construction and Hoover Dam, May 22, 2009." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge

Photographer's notes: "Aerial view looking down the canyon with the Nevada hairpin turn of the old highway in the foreground." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge

Photographer's notes: "Aerial view showing relationships among Hoover Dam, the original road between Arizona and Nevada, and the Hoover Dam Bypass under construction, May 22, 2009." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge

Photographer's notes: "Arch construction as seen from cliff over looking the Nevada hairpin turn, June 29, 2009." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge

Photographer's notes: "Arch construction view from Arizona side north of bridge, June 29, 2009." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge

Photographer's notes: "Arch construction view from Arizona side south of bridge, June 29, 2009." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge

Photographer's notes: "Ironworkers fabricate rebar forms on the Arizona side, then the forms were transported via highline crane into position for the next segment of arch construction, June 29, 2009." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge