Despite the cold weather in the area, the only recorded freeze-up of the river and falls was due to an ice jam on March 29, 1848. In 1912, the American Falls was also frozen but the other two kept running. Although the falls usually ice up most winters, the river and the falls do not freeze completely. The years 1885, 1902, 1906, 1911, 1932, 1936, 2014, 2017 and 2019 are noted for partial freezing of the falls.
A so-called ice bridge was also seen in certain years at the base of the falls and was used by people to cross the river when bridges had not been built. On 12 February 1912, the ice bridge began breaking up while people were walking and standing on it. Many could survive but three of them died during the event, later it was named the Ice Bridge Disaster or Tragedy.