Great Lakes

The Great Lakes are a chain of five interconnected freshwater lakes in east-central North America: Superior, Michigan, Huron, Erie, and Ontario.

The Great Lakes are a chain of five interconnected freshwater lakes in east-central North America: Superior, Michigan, Huron, Erie, and Ontario. They form a major natural boundary between Canada and the United States and drain to the Atlantic Ocean via the St. Lawrence River. The lakes are a major part of Canada’s southern boundary and are central to Canadian freshwater geography and cross-border management.

Geography

The Great Lakes are five large freshwater lakes in east-central North America. They are hydrologically connected and drain eastward through the St. Lawrence River into the Atlantic Ocean. The combined surface area of the lakes is about 244,106 km², and the basin area covers about 765,900 km².

Hydrology and basin

The Great Lakes Basin includes the lakes themselves plus the land and waterways that drain into them. The basin spans parts of both Canada and the United States, covering a much larger area than the lakes alone. It includes major parts of Ontario and Quebec on the Canadian side.

Canada–United States boundary

Except for Lake Michigan, the Great Lakes either lie on or help define the international boundary between Canada and the United States. Lake Michigan is the only Great Lake located entirely within the United States; the others form part of the Canada–United States border. Boundary waters along the lakes have long been managed through bilateral agreements.

Economic and ecological importance

The lakes support shipping, water supply, recreation, and habitat for a large freshwater ecosystem. The Great Lakes constitute the largest surface freshwater system in the world. They are widely described as one of North America’s defining natural features and are important for transportation, drinking water, recreation, and economic activity.