Due to the large volume of water that flows from Niagara Falls, it never actually freezes. Reports indicate that the water flow completely stopped for several hours on March 29, 1848 because of an ice jam in the upper river. This is the only time the flow paused naturally.
The mist and falling water can create ice formations alongside the falls and the river itself. If the temperature is low enough in the winter, Niagara Falls sometimes creates an ice bridge that extends across the entire river. The Niagara also carries ice chunks from Lake Erie known as "mini icebergs."