The Welland Canal was initially manmade back in 1829 with teams of work horses and carts. It allows the ships to go farther inland from Lake Ontario to Lake Erie. From Lake Erie they have access to Lake Huron, Lake Michigan, Lake Superior, to ports in Buffalo, Cleveland, Detroit, Chicago, all the way inland to Thunder Bay, Ontario and Duluth, Minnesota. The natural channel between these two lakes is the Niagara River. Because of the water falls, the boats use this manmade canal. Lake Erie is 99 meters, 326 feet, higher in elevation than Lake Ontario. There's a series of eight locks, or stages, that will raise or lower the boats.Coming from the Atlantic, they go 2000 kilometers, 1200 miles, to mid North America. Approximately 40,000,000 tonnes of cargo are carried through the Welland Canal annually by a traffic of about 3,000 ocean and Great Lakes vessels. This is part of the St. Lawrence Seaway, the Welland Canal, the only place where a ship could climb a mountain. The Great Lake freighters are specially designed to be narrow enough to fit through the locks.