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

Photographer's notes: "Aerial view of the bridge, dam and Lake Mead." 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: "Aerial view of bridge and the hairpin turn of the old Nevada road, June 30, 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 with half of the bridge's deck along the bottom edge of the frame, January 14, 2011." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge

Photographer's notes: "Aerial view of the structurally completed bridge showing its relationship to Hoover Dam and Lake Mead, July 31, 2010." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge

Photographer's notes: "View up to the Nevada side from the Arizona side of the powerhouse with the first of the final four tub girders installed, April 15, 2010. Note: Someone was the first person to walk across the span completed when this girder was installed. I never learned who that person was." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge