The St. Lawrence River is a grand river and estuary, which together with the Great Lakes forms a hydrographic system that penetrates 3,058 km into North America. The river proper, about 1,197 km long, issues from Lake Ontario, flows northeast past Montreal and Quebec City to the Gulf of St. Lawrence. The route of early explorers and the main axis of New France, the St. Lawrence River figured prominently in Canada’s early history, and it remains the focus of settlement for much of the province of Quebec. It is still the most important commercial waterway in Canada, as well as a source of electric power and natural beauty.