10 Deep Facts About the Great Lakes

The Devil's Island lighthouse in the Apostle Islands in Lake Superior.
The Devil's Island lighthouse in the Apostle Islands in Lake Superior. / Posnov/Moment/Getty Images

The Great Lakes of North America span 750 miles from east to west and form the largest freshwater system on Earth. Here are 10 facts about the fab five.

1. Lake Superior is the biggest and deepest—by far.

Lake Superior, the world’s largest freshwater lake, straddles the U.S.-Canada border and touches Minnesota, Wisconsin, and Michigan. In terms of surface area, the numbers are staggering: it’s 350 miles wide and 160 miles long. It boasts 31,700 square miles of surface water and 2726 miles of shoreline. The lake’s average depth of nearly 500 feet extends to a maximum depth of 1332 feet. Its volume of 2900 cubic miles is more than enough to fill all the other Great Lakes combined.

2. Lake Ontario and Lake Erie are the smallest.

Lake Erie, which borders Michigan, Ohio, Pennsylvania, and New York, measures 241 miles across and 57 miles long, larger than Lake Ontario’s 193-mile-by-53-mile footprint. But Erie’s average depth is just 62 feet and has a volume of around 119 cubic miles, much smaller than Ontario’s average depth of 283 feet and volume of 395 cubic miles. The two lakes are connected by the 35-mile long Niagara River.

3. Only one Great Lake is located entirely within the U.S.

The Chicago skyline looms over Lake Michigan.
The Chicago skyline looms over Lake Michigan. / Fraser Hall/The Image Bank/Getty Images

As its name suggests, Lake Michigan and its 1180 cubic miles of water, 22,300 square miles of surface water, and 1600 miles of shoreline is the only one of the Great Lakes that lies entirely within American borders. It is the second-largest of the Great Lakes by volume and is connected to Lake Huron by the Straits of Mackinac between Michigan’s upper and lower peninsulas.

4. You can take a 6500-mile road trip around the Great Lakes.

The Great Lakes Commission established the Circle Tour in 1988 as a scenic tourist drive around the five lakes and through the eight bordering states and Ontario, Canada. Just to navigate Lake Michigan’s 900-mile Circle Tour alone would take approximately 14.5 hours without any stops.

5. A fire prompted massive environmental reforms for the Great Lakes.

A fire on Ohio’s Cuyahoga River in June 1969, and the iconic image that was published thereafter, helped spur a number of environmental regulations aimed at cleaning up the waterway that feeds Lake Erie, as well as America’s lakes and rivers in general. Amendments to the Federal Water Pollution Control Act, now known as the Clean Water Act, were enacted in 1972 regulating water pollution and discharge, and gave the Environmental Protection Agency broader pollution control powers. In addition, the United States and Canada signed the Great Lakes Water Quality Act in 1972 to “restore and protect the waters of the Great Lakes.”

6. The Great Lakes contain more than 35,000 islands.

Georgian Bay islands.
Georgian Bay islands. / Posnov/Moment/Getty Images

Of the thousands of islands scattered throughout the lakes, the largest is Manitoulin in Lake Huron. It is the largest freshwater lake island in the world at 1068 square miles and has a population of around 13,000. Georgian Bay, a part of Lake Huron, includes about 17,500 islands, while the archipelago in the St. Lawrence River known as the Thousand Islands actually encompasses around 1800 islands.

7. Each lake’s name is derived from an Indigenous language or French.

Lake Erie is named for the Erie people who lived along the lake’s southern shores; Erie is a shortened version of the Iroquoian word erielhonan, meaning “long tailed,” or alternatively rhiienhonons, “raccoon nation.” Lake Michigan’s name comes from a French spelling of the Old Ojibwe term meshi-gami, “big lake.” Huron is an obsolete French adjective meaning “bristle-haired,” which may have referred to the headdresses of the Native people that French settlers encountered in the region. Ontario comes from the Mohawk word ontari:io, “beautiful lake.” And finally, French explorers dubbed the largest of the Great Lakes le lac supérieur, or “upper lake.”

8. Shipping is still a dominant industry on the Great Lakes.

The Canadian and U.S. lake fleets, made up of carriers, tankers, bulk freighters (“lakers”), tugs, and barges, transport more than 100 million tons of cargo a year. The main cargoes are iron ore, coal, and limestone, while major agricultural shipments contains wheat, corn, sorghum, and soybeans. Other cargo includes steel, scrap metal, iron products, fuel, and chemicals.

9. The largest fish in the Great Lakes can weigh more than 200 pounds.

A lake sturgeon.
A lake sturgeon. / Detlev Loll/EyeEm/Getty Images

Fishing is a revered pastime on the Great Lakes, one of the largest freshwater fisheries in the world. There are 139 native fish species, including lake whitefish, yellow perch, walleye, lake trout, large and smallmouth bass, coho and Atlantic salmon, and muskellunge. Lake sturgeon are the biggest species of fish found in the lakes; these ancient fish can weigh up to 300 pounds and grow to 6 feet long.

10. Lake Superior is full of shipwrecks.

While the wreck of the famed S.S. Edmund Fitzgerald on Lake Superior has generated a hit song, memorials, and conspiracies surrounding its sinking, a number of other commercial ships have sunk around Whitefish Bay near Whitefish Point, Michigan. The wooden steamerVienna sank in 1892 on Lake Superior and is now a popular spot for divers; the Comet also sank on Lake Superior and took 11 lives with it in 1875; the John M. Osborn collided with the Alberta in 1884 and drowned four crew members; and on its second voyage, the S.S. Cyprus sank near Deer Park, Michigan, in 1907, killing 22 of its 23 crew members.

The dangerous stretch of water on southern Lake Superior between Munising, Michigan, and Whitefish Point has been called the “Graveyard of the Great Lakes” and “Shipwreck Coast,” because hundreds of ships have been lost in the area. It’s estimated that 6000 ships have sunk in the five Great Lakes with a loss of nearly 30,000 lives.

A version of this story was published in 2016; it has been updated for 2023.