Photographer's notes: "With the bridge complete and open, the bridge, dam and lake now share the Black Canyon. January 14, 2011. Note: This is the uncropped version of this photograph. I chose to crop out the horizon for use in the book and exhibition." 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

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

Photographer's notes: "Aerial view, the pedestrian walkway "switchbacks" up to informational/historical displays and the pedestrian walkway on the bridge can be seen from the lower left of the frame moving across the bridge. April 10, 2012." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge

Photographer's notes: "View of the highline crane system from the Nevada side looking toward Arizona, March 4, 2009." Site Name: Mike O'Callaghan-Pat Tillman Memorial Bridge