Photographer's notes: "View from the Nevada bridge deck down to the Nevada side arch segments and Colorado River." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge

Photographer's notes: "View from the Nevada bridge deck down to a Nevada side arch segment and Colorado River." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge

Photographer's notes: "View from a narrow side canyon used by the lower access road down to the dam. Note: This is one of the few photographs where I supplemented existing light by adding a flash to give the cliff on the right and the road some detail." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge

Photographer's notes: "Final concrete pour, which formed the keystone of the arch and completed its structure. Note: This photograph required a very last minute rush trip from Santa Fe to the Bridge. I got the call in the early afternoon and arrived to shoot just at sunset." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge

Photographer's notes: "Aerial view, April 10, 2012. Note: I was commissioned to photograph over the bridge and dam in April 2012, more than a year after my project was complete." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge

Photographer's notes: "Aerial view, April 10, 2012. Note: I was commissioned to photograph over the bridge and dam in April 2012, more than a year after my project was complete." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge