About the Great Lakes St. Lawrence Basin

The Great Lakes-St. Lawrence River Basin is located within the U.S. States of Illinois, Indiana, Michigan, Minnesota, New York, Ohio, Pennsylvania and Wisconsin, as well as the Canadian Provinces of Ontario and Quebec.  

Containing more than 20% of the world's surface water, the Great Lakes-St. Lawrence Basin is the single largest watershed in the world, ranging from Trois-Rivières, Québec to the western point of Lake Superior.  The Basin contains over 94,000 square miles of surface water, and is the world's largest inland water system, extending over 3800 miles.

  Lake Erie Lake Huron Lake Michigan Lake Ontario Lake Superior
Surface area 9,910 sq mi (25,700 km2) 23,000 sq mi (60,000 km2) 22,300 sq mi (58,000 km2) 7,340 sq mi (19,000 km2) 31,700 sq mi (82,000 km2)
Water volume 116 cu mi (480 km3) 850 cu mi (3,500 km3) 1,180 cu mi (4,900 km3) 393 cu mi (1,640 km3) 2,900 cu mi (12,000 km3)
Elevation 571 ft (174 m) 577 ft (176 m) 577 ft (176 m) 246 ft (75 m) 600.0 ft (182.9 m)
Average depth 62 ft (19 m) 195 ft (59 m) 279 ft (85 m) 283 ft (86 m) 483 ft (147 m)
Maximum depth 210 ft (64 m) 748 ft (228 m) 925 ft (282 m) 804 ft (245 m) 1,333 ft (406 m)