Great Lakes region
Freshwater seas of North America — trade, ecology, and climate.
The Great Lakes — Superior, Michigan, Huron, Erie, and Ontario — form the largest surface freshwater system on Earth by area. They sit on the U.S.–Canada border and connect to the Atlantic via the St. Lawrence River.
These lakes modulate regional weather, supply drinking water to tens of millions, and support shipping, manufacturing, and recreation across the U.S. Midwest and Ontario.
- Lake effect snow — cold air crossing open water dumps winter snow downwind.
- Invasive species — ballast water and canals reshaped food webs.
- Water levels — multi-year swings affect shorelines and infrastructure.
See also: Mississippi Basin, Climate zones.
