What rivers go into niagara falls?

Niagara Falls is fed by the Niagara River, which flows from Lake Erie to Lake Ontario. The Niagara River is actually a strait, as it connects the two Great Lakes. The Niagara River is about 36 miles long, and has a drainage basin of about 250,000 square miles. The Niagara River is also the source of hydroelectric power for both Canada and the United States.