Ontario and the Great Lakes: Bordering All Five, Containing None

Shoreline Steward, Not Sole Owner

Ontario shares a shoreline with all five Great Lakes (Superior, Huron, Erie, Ontario, Michigan via Georgian Bay/North Channel), but does not fully contain any of them within its provincial boundaries.

Lake-by-Lake

Key Implications

• Binational Management: Great Lakes Water Quality Agreement (1972, updated), IJC (International Joint Commission). Ontario = key partner.
• Water Withdrawals: Ontario implements Great Lakes–St. Lawrence River Basin Compact (via provincial legislation).
• Economy: 98% of Ontarians live in Great Lakes basin. Toronto, Hamilton, London, Windsor, Thunder Bay all on lakes.
• Lake Michigan Exception: Only lake entirely in US. Ontario touches it only via Georgian Bay/North Channel (hydrologically same lake).

Ontario is the Canadian Great Lakes guardian—with the most shoreline (10,000+ km) and population dependent on them.