This photo is from a scanned slide taken on a visit in 1969. At the time of our visit, the flow over the American Falls had been stopped completely for several months in 1969.
The idea was to determine the feasibility of removing the large amount of loose rock from the base of the falls to enhance its appearance.
In the end the final decision was that the expense would be too great.
You can easily see that there was only a trickle of water flowing over the American Falls at the time of our visit.