The Falls at Niagara are about 12,000 years old. This is relatively young compared to other waterfalls in the world. Some are up to 2.5 million years old!
Here’s the Coles Notes version of how our falls were formed. During the Glacial Epoch of the Earth’s history (500,000 to 2 million years ago,), glaciers melted and formed lakes. Lake Algonquin (located where Lake Erie is now) overflowed and ran downhill to Lake Iroquois (where Lake Ontario is now). The rushing water we know as the Niagara River dug out a path to Lake Iroquois. The falls were formed the riverbed dropped off suddenly like an underwater cliff. Water raced over this cliff forming Niagara Falls.
It’s estimated that 10,000 years from now the falls will cease to exist when it makes its way to Lake Erie. Good thing we’re here to see this magnificent waterfall!