St. Lawrence River

North America · Great Lakes · international waterway

Connects the Great Lakes. The St. Lawrence River flows northeast from Lake Ontario all the way to the Gulf of St. Lawrence and the Atlantic Ocean. It's the main water route that lets cargo ships travel from the Great Lakes to the ocean.

International border river. Part of the St. Lawrence forms the boundary between Canada and the United States, with Ontario and Quebec on one side and New York on the other. This shared river connects two countries.

Powerful water flow. The river's strong current and waterfalls made it a great source of power, and today hydroelectric dams harness its energy to generate electricity for millions of people.

Major shipping route. Ships carrying cargo, iron ore, and grain use the St. Lawrence to travel between the interior of North America and ports around the Atlantic Ocean.

Winter freezing. In the coldest months, parts of the river can freeze over, though the flowing water near dams often stays open longer than other sections.