The St. Lawrence Seaway () is a system of locks, canals, and channels in Canada and the United States that permits oceangoing vessels to travel from the Atlantic Ocean to the Great Lakes of North America, as far inland as Duluth, Minnesota, at the western end of Lake Superior. The seaway is named for the St. Lawrence River, which flows from Lake Ontario to the Atlantic Ocean. Legally, the seaway extends from Montreal, Quebec, to Lake Erie, and includes the Welland Canal. Ships from the Atlantic Ocean are able to reach ports in all five of the Great Lakes. The St. Lawrence River portion of the seaway is not a continuous canal; rather, it consists of several stretches of navigable channels within the river, a number of locks, and canals along the banks of the St. Lawrence River to bypass several rapids and dams. A number of the locks are managed by the St. Lawrence Seaway Management Corporation in Canada, and others in the United States by the St. Lawrence Seaway Development Corporation; the two bodies together advertise the seaway as part of "Highway H2O". The section of the river from Montreal to the Atlantic is under Canadian jurisdiction, regulated by the offices of Transport Canada in the Port of Quebec. History The St. Lawrence Seaway was preceded by several other canals. In 1871, locks on the St. Lawrence allowed transit of vessels long, wide, and deep. The First Welland Canal, constructed between 1824 and 1829, had a minimum lock size of long, wide, and deep, but it was generally too small to allow passage of larger oceangoing ships. The Welland Canal's minimum lock size was increased to long, wide, and deep for the Second Welland Canal; to long, wide, and deep with the Third Welland Canal; and to long, wide, and deep for the current (Fourth) Welland Canal. The first proposals for a binational comprehensive deep waterway along the St. Lawrence were made in the 1890s. In the following decades, developers proposed a hydropower project as inseparable from the seaway; the various governments and seaway supporters believed the deeper water to be created by the hydro project was necessary to make the seaway channels feasible for oceangoing ships. U.S. proposals for development up to and including the First World War met with little interest from the Canadian federal government. But the two national governments submitted St. Lawrence plans to