What is the Great Lakes Waterway’s approximate navigable length?

The Great Lakes Waterway has an approximate navigable length of 3,769 kilometres. It is a connected system of natural channels, rivers, canals, locks, and dredged routes that lets commercial vessels travel between the Great Lakes and the Atlantic Ocean.

The route follows the lakes and their connecting waterways, including the Saint Marys River, Lake Huron, the St. Clair River, Lake St. Clair, the Detroit River, Lake Erie, the Welland Canal, Lake Ontario, and the Saint Lawrence River. Different sources can quote slightly different distances because they measure different shipping routes and endpoints.

The waterway is not one single artificial canal. Much of it consists of naturally connected lakes and rivers, while engineered structures overcome rapids, waterfalls, shallow stretches, and changes in elevation. The Welland Canal is especially important because it allows ships to bypass Niagara Falls.

Ocean-going and “laker” vessels use different parts of the system, with vessel size limited by locks, channels, bridges, and seasonal conditions.