Photographer's notes: "Sunrise, looking across the canyon to Nevada. The arch was nearly complete with temporary pylons and cable stays supporting each segment. The highline crane system prepared to lower a rebar section into position." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge

Photographer's notes: "Workers arriving to work via the highline crane and manbasket, July 1, 2009." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge

Photographer's notes: "View from the Arizona pylons toward arch construction and Nevada. The cable stays were covered in white in reduce expansion and contraction from the desert sun and heat. Note: This was the only evening I was allowed on top of the temporary pylons to shoot." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge

Photographer's notes: "On the end of the Nevada arch segment, ironworkers prepared formwork prior to pouring the next concrete section, July 1, 2009." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge

Photographer's notes: "On the end of the Nevada arch segment, ironworkers prepared formwork prior to pouring the next concrete section. Note: This was the only evening I was allowed on top of the temporary pylons to shoot." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge

Photographer's notes: "Nighttime view from the top of the temporary pylons down to the Arizona bridge deck, July 1, 2009." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge

Photographer's notes: "View from the dam sidewalk downstream toward the bridge, before dawn, July 2, 2009." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge