History of Niagara Falls

side of the falls, and the engineers were to clean up the rock and repair some faults to prevent eventual erosion of the American side of the waterfall. A temporary dam was constructed to divert the flow of water to the Canadian side; the dam measured 600 feet (180 m) across and was made of nearly 30,000 tons of rock. The engineers cleared the rock debris and tested for safety, finishing the project in November of that year. Water flow was restored on November 25, 1969.

Before the late 20th century the northeastern end of the Horseshoe Falls was in the United States, flowing around the Terrapin Rocks, which was once connected to Goat Island by a series of bridges. In 1955 the area between the rocks and Goat Island was filled in, creating Terrapin Point. In the early 1980s the United States Army Corps of Engineers filled in more land and built diversion dams and retaining walls to force the water away from Terrapin Point. Altogether 400 feet (120 m) of the Horseshoe Falls was eliminated, including 100 feet (30 m) on the Canadian side. According to author Ginger Strand, the Horseshoe Falls is now entirely in Canada. Other sources say "most of" Horseshoe Falls is in Canada