Aerial view showing the twelve central girders installed as support for the eventual bridge deck, February 3, 2010. Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge

Photographer's notes: "Aerial view of a motor boat on Lake Mead near the mineral deposit banding that revealed the lower level of the Lake Mead reservoir, June 30, 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: "Cable stays supported arch construction until the arch was complete. Formwork at the end of the arch segment created the framework for pouring each new concrete section." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge

Photographer's notes: "View of the Arizona side of the bridge with Sugarloaf in the background. With the bridge unlit at night, except along the pedestrian walkway (still under construction), evening illumination comes from the lighting of the dam and the moonlight. July 26, 2010." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge

Photographer's notes: "The form and structure of the bridge, its arch, piers and girders, are revealed in a view from the Nevada canyon wall near the old Nevada hairpin turn. The reflected light of Hoover Dam provides the primary night time illumination of this side of the bridge. January 12, 2011." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge

Photographer's notes: "While the bridge was substantially complete, the roadways leading to the bridge on both sides awaited completion, July 31, 2010." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge