The "original" Niagara Falls was located approximately 7 miles (11 kilometers) north of its current position, near what are now the towns of Lewiston, New York, and Queenston, Ontario. Since the falls were formed about 12,500 years ago at the end of the last Ice Age, the sheer force of the water has caused the underlying rock to erode, moving the falls steadily upstream toward Lake Erie. Historically, the falls receded at a rate of about 3 feet (1 meter) per year. However, in the mid-20th century, massive engineering projects were undertaken to slow this process. Today, a significant portion of the water from the Niagara River is diverted through massive tunnels for hydroelectric power generation, which has reduced the erosive force. Additionally, the falls were famously "turned off" on the American side in 1969 to allow engineers to study the rock face and remove loose boulders. In 2026, due to these interventions, the erosion rate has slowed to just a few inches every decade, effectively "freezing" the falls in their current iconic Horseshoe and American configurations for future generations to witness.