Saint Lawrence Seaway and Great Lakes Waterway

Saint Lawrence Seaway and Great Lakes Waterway, U.S./Canadian inland waterway for oceangoing vessels connecting the Great Lakes with the Atlantic Ocean, and comprising a system of natural waterways, canals, locks, dams, and dredged channels (including the Welland Ship Canal) 2,342 mi (3,769 km) long. A joint venture between the United States and Canada, it was completed in 1959.