Saint Lawrence Seaway
The seaway then leaves Quebec through Lac Saint-François and the Akwesasne Mohawk First Nation, and passes through New York State and Ontario. In New York, the Wiley-Dondero Canal (Snell and Eisenhower locks) passes the Moses-Saunders power dam, and the short Iroquois lock passes the Iroquois water level control structure.
The Saint Lawrence Seaway is often considered together with the Great Lakes Waterway: the Welland Canal which passes Niagara Falls, and the Sault locks that pass Sault Ste. Marie.
The seaway is co-administered by Canada and the United States. It was first used on April 25, 1959, although it wasn't officially opened until June 26th, 1959.
To create a navigable channel through the Long Sault rapids and allow hydroelectric stations to be established at Cornwall, Ontario and Massena, New York, a man-made lake, Lake Saint Lawrence, was created. This required the inundation on July 1, 1958 of seven villages, "The Lost Villages", in Ontario.
The creation of the Seaway also led to the introduction of foreign species of aquatic animals, including the sea lamprey and the zebra mussel, into the Great Lakes watershed.