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St. Lawrence River

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description St. Lawrence River Overview

The St. Lawrence River is a large hydrological system in North America that connects the Great Lakes to the Atlantic Ocean. It flows northeast for approximately 1,197 kilometers, forming part of the international boundary between the United States and Canada. The river serves as the primary drainage outlet for the Great Lakes Basin and includes the St.

Lawrence Seaway, a navigational project enabling ocean-going vessels to travel inland. It is essential for commercial shipping, hydroelectric power generation, and regional ecology.

help St. Lawrence River FAQ

Where does the St. Lawrence River begin and end?

The river flows from Lake Ontario northeast toward the Gulf of St. Lawrence and the Atlantic Ocean. Along the way it passes major cities including Montreal and Quebec City.

Why is the St. Lawrence River important to Great Lakes shipping?

Together with canals and locks of the St. Lawrence Seaway, it gives oceangoing vessels access between the Atlantic and the Great Lakes. The system supports ports in both Canada and the United States.

Does the St. Lawrence River form the Canada-US border?

Part of the upper river forms an international boundary between Ontario and New York. Farther downstream, the river flows entirely within Canada, principally through Quebec.

Where are the Thousand Islands on the St. Lawrence?

The Thousand Islands archipelago lies near the river's outlet from Lake Ontario, straddling the Canada-US border. The islands are associated with communities such as Kingston and Gananoque in Ontario and Alexandria Bay in New York.

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