No, Niagara Falls is a natural wonder, formed approximately 12,500 years ago at the end of the last Ice Age as melting glaciers created the Great Lakes and the Niagara River carved a path through the Niagara Escarpment. However, while the falls themselves are natural, they are perhaps the most "managed" waterfalls in the world. The flow of water is heavily controlled by the governments of the United States and Canada for hydroelectric power generation. Under the 1950 Niagara Treaty, a portion of the water is diverted through massive tunnels to power stations, particularly at night and during the winter. This diversion actually helps slow down the erosion of the falls, which would otherwise recede at a much faster rate. Furthermore, significant "man-made" engineering has taken place to improve the safety and aesthetics of the site, such as the 1969 "de-watering" of the American Falls to study the rock face and remove loose boulders (talus) from the base. So, while the water and the geological drop are 100% natural, the way the water flows today is a carefully balanced act of international engineering and environmental management.
The Niagara River is a river that flows north from Lake Erie to Lake Ontario. It forms part of the border between the province of Ontario in Canada and the state of New York in the United States. There are differing theories as to the origin of the river's name.