Tourists walk along Las Vegas Boulevard across the street from the Mirage Hotel and Casino. Many sidewalks are protected from traffic lanes by physical barriers, where others are not. Moving pedestrians along the Strip safely has become a major effort over the years.

Description provided with image: "Symposium held at UNLV to honor Dr. David Bruce Dill of Boulder City, research professor for Desert Research Institute. (Dr. Dill is in front row, between lady wearing striped blouse and lady in white. He is 80 years old)."

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

A photograph of Maya Miller, International Women's Year (IWY) Coordinating Committee; Jo Gonzales, luncheon mistress of ceremonies; and Gloria Steinem, keynote speaker, at the Nevada Women's Conference that was held in Las Vegas in 1977. Site Name: Las Vegas Convention Center