5 lakes · 8 states · about 94,000 sq mi · Superior is the largest freshwater lake by area on earth
Great Lakes map
Superior, Michigan, Huron, Erie and Ontario hold about a fifth of the world's surface fresh water and touch eight states. Lake Michigan is the only one entirely inside the United States.
Where the Great Lakes are
The five lakes lie along the US–Canada border between Minnesota and New York. Water flows from Superior through the St. Marys River into Huron, from Michigan through the Straits of Mackinac into Huron (the two are one lake hydrologically), from Huron down the St. Clair and Detroit rivers into Erie, over Niagara Falls into Ontario, and out the St. Lawrence River to the Atlantic. The international boundary runs through the middle of four lakes; Lake Michigan is wholly American.
The five lakes
| Lake | Area (sq mi) | Max depth (ft) | Surface elevation (ft) | US states |
|---|---|---|---|---|
| Superior | about 31,700 | 1,333 | about 600 | MN, WI, MI |
| Huron | about 23,000 | 750 | about 577 | MI |
| Michigan | about 22,300 | 925 | about 577 | MI, WI, IL, IN |
| Erie | about 9,900 | 210 | about 569 | MI, OH, PA, NY |
| Ontario | about 7,300 | 802 | about 243 | NY |
Superior is the largest freshwater lake in the world by surface area and holds about half of all the water in the system. Erie is the shallowest and warmest, which is why it freezes and why its algae blooms make news. The 326-ft drop between Erie and Ontario is Niagara Falls, bypassed for ships by Canada's Welland Canal.
States on the lakes
- Michigan — touches Superior, Michigan, Huron and Erie, with about 3,200 miles of shoreline, more than any state but Alaska.
- Wisconsin — Superior (Superior, Ashland) and Michigan (Milwaukee, Green Bay, Door County).
- Minnesota — Superior, with Duluth at the western tip, the farthest inland seaport in the world at about 2,300 miles from the Atlantic.
- Illinois — 63 miles of Lake Michigan shore, almost all of it Chicago and its suburbs.
- Indiana — 45 miles of Lake Michigan shore, including Gary and Indiana Dunes National Park.
- Ohio — Erie, from Toledo through Sandusky and Cleveland to Conneaut.
- Pennsylvania — about 50 miles of Erie shore around the city of Erie.
- New York — Erie (Buffalo) and Ontario (Rochester, Oswego).
Cities on the lakes
Chicago is by far the largest, followed by Detroit (on the Detroit River between Huron and Erie), Milwaukee, Cleveland, Buffalo, Toledo, Rochester, Erie, Duluth and Green Bay. Toronto and Hamilton face New York across Lake Ontario. Ships from the Atlantic reach all of them through the St. Lawrence Seaway (1959) and the Soo Locks at Sault Ste. Marie, which lift vessels 21 ft between Huron and Superior.
How the lakes shaped the map
The 1783 Treaty of Paris put the border through the lakes, and the Northwest Ordinance used them as the northern edge of the future Midwest. Michigan's odd shape, two peninsulas joined only by the 5-mile Mackinac Bridge, is a result of the 1835–1836 Toledo War: Michigan gave up the Toledo strip to Ohio and received the Upper Peninsula, previously expected to go to Wisconsin. Illinois' northern border was moved north in 1818 specifically to give the state a Lake Michigan port at Chicago. The Erie Canal (1825) tied the lakes to the Hudson and made New York the leading port.
Related maps
- Largest US lakes — the Great Lakes compared with Great Salt Lake, Okeechobee and others.
- Great Lakes states — the region page.
- Hudson River · Mississippi River — the Chicago canal links the two basins.
- Eastern and Central time zones — the line runs between Indiana/Michigan and Illinois/Wisconsin along the lake.
- All geography maps.