And nobody was talking about "global warming" at the time.
For six months in the summer and fall of 1969, Niagara’s American Falls were “de-watered”, as the Army Corps of Engineers conducted a geological survey of the falls’ rock face, concerned that it was becoming destabilized by erosion. These stark images reveal North America’s iconic – and most powerful – waterfall to be almost as dry as a desert.
Niagara Falls is the collective name for three waterfalls that straddle the international border between Canada and the United States. From largest to smallest, the three waterfalls are the Horseshoe Falls, the American Falls and the Bridal Veil Falls.
The Horseshoe Falls lie mostly on the Canadian side and the American Falls entirely on the American side, separated by Goat Island. The smaller Bridal Veil Falls are also on the American side, separated from the other waterfalls by Luna Island.