The Great Lakes are a chain of deep freshwater lakes in east-central North America comprising the lakes Superior, Michigan, Huron, Erie, and Ontario.

Their drainage basin of about 295,710 square miles (which includes the areas of the lakes themselves and their connecting waterways) extends approximately 690 miles from north to south and about 860 miles from Lake Superior in the west to Lake Ontario in the east. Except for Lake Michigan, the lakes provide a natural border between Canada and the United States, a frontier that was stabilized by a boundary-waters treaty of 1909. It is a source of pride for both countries that there are no fortifications or warships along the boundary.

Areas and volumes of the Great Lakes

(“Renewal” is a measurement of how long it would take for tributaries to refill the lake)

(“1 cubic mile” contains 1.1 trillion gallons

Have the Great lakes ever frozen over?

The highest ice coverage on record was 94.7% in 1979, when Lake Superior almost entirely froze over.

On February 10, 2014, 87.1% was total ice area for all 5 lakes.

The Great Lakes contain about 21% of the world's fresh surface water and about 84% of the United States' fresh surface water - about 5,439 cubic miles (about six quadrillion gallons) measured at low water level. That's enough water to cover the entire continental U.S. with 9.5 feet of water!

Large ships can transport cargo through the Great Lakes and into the Atlantic Ocean by way of the Saint Lawrence Seaway.

Billions of dollars worth of fuel, construction materials, agricultural products, manufactured goods, and raw materials are transported to ports on the Great Lakes every day.

Water in the Great Lakes flows from Lake Superior, into Lake Huron, into Lake Michigan, into Lake Erie, into Lake Ontario, and into the Atlantic Ocean through the Saint Lawrence River.

Formed by the Niagara River, which drains Lake Erie into Lake Ontario, the combined falls have the highest flow rate of any waterfall in North America that has a vertical drop of more than 160 ft. During peak daytime tourist hours, more than 5.9 million cu ft of water goes over the crest of the falls every minute. Horseshoe Falls is the most powerful waterfall in North America, as measured by flow rate. Niagara Falls is famed for its beauty and is a valuable source of hydroelectric power.

Horseshoe Falls

There are about 35,000 islands in the Great Lakes, many of which are inhabited. People travel between the island and the mainland by ferries, boats, and bridges.

The Canadian province of Ontario and eight U.S. states (Illinois, Indiana, Michigan, Minnesota, New York, Ohio, Pennsylvania, and Wisconsin) have shorelines on the lakes.

All of the lakes except Erie are deep enough that their bottoms are below sea level.

The shape, location and depth of the lakes were mainly determined by repeated episodes of glacial erosion during the Great Ice Age.

What kinds of fish are found in the Great Lakes?

Some of the most common and popular fish in the Great Lakes are salmon, trout, and bass. These fish are prized by anglers for their size, fight, and taste. Salmon and trout are cold-water fish that thrive in deep and cold areas of the lakes, especially Lake Superior and Lake Michigan. They include species such as chinook salmon, coho salmon, rainbow trout, brown trout, lake trout, and brook trout. Bass are warm-water fish that prefer shallow and warm areas of the lakes, especially Lake Erie and Lake St. Clair. They include species such as smallmouth bass, largemouth bass, rock bass, and white bass.

Some of the most unique and rare fish in the Great Lakes are sturgeon, lake whitefish, and smelt. These fish are native to the Great Lakes and have adapted to their specific habitats and conditions. Sturgeon are ancient fish that can grow up to 8 feet long and weigh over 200 pounds. They have bony plates on their bodies and long snouts with whisker-like barbels. They live in deep and murky areas of the lakes, especially Lake Huron and Lake Ontario. Lake whitefish are silvery fish that can grow up to 20 inches long and weigh up to 10 pounds. They have small mouths and large scales on their bodies. They live in cold and clear areas of the lakes, especially Lake Superior and Lake Huron. Smelt are small fish that can grow up to 9 inches long and weigh up to 3 ounces. They have slender bodies and large eyes on their heads. They live in cold and open areas of the lakes, especially Lake Michigan and Lake Huron.

The Great Lakes are home to many other kinds of fish, both native and introduced. Some of them are walleye, yellow perch, muskellunge, northern pike, freshwater drum, round goby, ruffe, alewife, gizzard shad, carp, goldfish, grass carp, silver carp, bighead carp, oriental weatherfish, banded killifish, brook silverside, trout-perch, pirate perch, burbot, mottled sculpin, white perch, white crappie, black crappie, yellow bullhead, channel catfish, rainbow smelt, bloater, pink salmon, Atlantic salmon, longnose gar, bowfin, American eel, longnose sucker, white sucker, silver redhorse, shorthead redhorse,

About 44,000 metric tons of fish are harvested commercially each year from the five lakes, with Lake Erie accounting for more than half of the total catch.

Lighthouses of the Great Lakes

The Great Lakes currently has over 200 active lighthouses guiding boats around the over 11,000 miles of shoreline. Many of these lighthouses date back to the early 1800s, built with lenses from France powerful enough to cast light across the water for miles. Today, some of these lighthouses are still operational, using automated lights that are less powerful but no less fascinating to enthusiasts. Big Bay Point Lighthouse offers the opportunity to stay overnight in historic lakeside light. Some in the U.P. say Big Bay Point Lighthouse is haunted, but that might make your stay even more exciting!

The complex shorelines and ever-changing depths show that the lighthouses are not just for beauty but function. They keep the ships from encountering shallow waters.

Shipwrecks in the Great Lakes

The tales of shipwrecks and treasure often enchant visitors to the Great Lakes area, which are filled with the mystery and intrigue of over 6,000 wrecks, many of which were never found. The depths of the Great Lakes became the final resting place of many ships because the basin offers no natural protection, leaving the ships exposed when storms blow through the lakes.

Lake Erie is believed to have the most shipwrecks (around 2,000) perfectly preserved in the cold fresh water. Wrecks can be found throughout the Great Lakes in shallow waters and can be enjoyed while snorkeling or on a glass-bottom boat tour.

Do tides affect the Great lakes?

Tides exist in all bodies of water, even one's bathtub, but is so infinitesimally small, as to be unmeasurable. Even on Lake Superior, the largest of the Great Lakes, the tiny effect of a tide is overcome by the effect of barometric pressure and the phenomenon known as a seiche. There are no Tide Tables of the Great Lakes and seiche warnings are rarely broadcast, as most cause a variance of less than 20 inches. The effects of a seiche are felt strongest in Lake Erie and the Straits of Mackinac between Lakes Huron and Michigan.

Is it possible to navigate a boat between the Atlantic Ocean and Lake Superior?

The St. Lawrence Seaway is a binational waterway that consists of 15 locks, 13 Canadian and 2 American, that lift vessels 551 feet above sea level as they transit from Montreal to Lake Erie. The seaway also includes the Welland Canal, which bypasses Niagara Falls, and the Soo Locks, which enable ships to reach Lake Superior, which is 600 feet above sea level. The seaway is open for about nine months of the year, from late March to late December, and attracts hundreds of commercial vessels from over 50 countries.

Lake Superior

Lake Superior first took shape about 1.2 billion years ago as a result of the North American Mid-Continent Rift, which carved an arc-shaped scar stretching from Kansas through Minnesota. The first people to settle in the region arrived around 8000 B.C., after glaciers retreated. By 500 B.C., Laurel people were trading for metal and other goods with different regions. By the early 1600’s, the Ojibway people had established a village of several thousand on Madeline Island.

A ship approaches the Duluth Pier Lighthouse. Lake Superior is a major shipping hub.

The lake's name comes from the French word lac supérieur, which means "upper lake." It called this because it is north of Lake Huron, which was discovered first by Brûlé. The Objibways said that the lake was protected by Nanabijou, spirit of the Deep Sea Water.

Superior was a major mode of transportation for the fur industry and other trading activities during the colonial period and remains a shipping hub today.

Because of varying depths and unpredictable weather, Lake Superior and the other Great Lakes have been prone to maritime accidents. One of the most well-known incidents occurred on November 10, 1975, when the Edmund Fitzgerald, a large cargo ship carrying iron ore, encountered a severe storm that killed the ship's 29 crew members.

Lake Superior is home to about 80 species of fish, including carp and varieties of trout, salmon, and perch.

The Lake Superior region is also home to many common native plant species, including Michigan's state tree, the white pine, and Flowering Rush, an aquatic plant that grows along the shoreline. Lake Superior's basin is home to nearly 60 orchid species.

As with many lakes, Lake Superior is home to many species of birds, including varieties of hawks, loons, owls and woodpeckers. Duluth's Hawk Ridge, which is on the lake's north shore, hosts as many as 10,000 migrating birds of prey each day during the fall migration season.

There is a small population of endangered whooping cranes on the lake's north shore, one of only two crane species in North America.

As of 2017, there were only 483 individuals in the wild across North America, according to the International Union for Conservation of Nature.

Lake Michigan

Lake Michigan is the only one of the five Great Lakes located fully in the United States; the other four are shared between the United States and Canada. Lake Michigan is the world's largest lake by area located fully in one country. It is shared, from west to east, by the U.S. states of Wisconsin, Illinois, Indiana, and Michigan. Ports along its shores include Chicago in Illinois, Gary in Indiana, Milwaukee and Green Bay in Wisconsin, and Muskegon in Michigan. The lake is flanked by multiple long bays, including Green Bay in the northwest, and Grand Traverse and Little Traverse bays in the northeast. The word "Michigan" is believed to come from the Ojibwe word (michi-gami or mishigami) meaning "great water" or “large lake”.

Twelve million people live along Lake Michigan's shores, mainly in the Chicago and Milwaukee metropolitan areas.

The Milwaukee lakefront

Chicago’s Oak Street Beach

The economy of many communities in northern Michigan and Door County, Wisconsin, is supported by tourism, with large seasonal populations attracted by Lake Michigan. Many seasonal residents have summer homes along the waterfront and return to other homes for the winter. The southern tip of the lake near Gary, Indiana, is heavily industrialized.

Much like the Bermuda Triangle, Lake Michigan has a mysterious triangle of its own. Often referred to as the Michigan Triangle, it spans from Manitowoc, Wisconsin, to Ludington, Michigan, and south to Benton Harbor. In 1891, strange events started happening in that area, including the complete disappearance of a schooner; not even a trace of which was ever found. This triangle has been blamed for inexplicable accidents, the disappearance of people, and even the vanishing of a commercial airplane in 1950. Wood maps of this area detail the depths and complexities of the lake bottom, but none explain the Triangle phenomenon.

Some yoopers credit a Stonehenge-like structure that lies beneath the waters of Lake Michigan with the peculiar happenings. Natives and visitors alike ask the question, “Could an ancient formation of rocks be to blame for the mysteries of the Triangle?” Or is there another Great Lakes myth at work?

Lake Huron

Lake Huron was originally called La Mer Douce, or “the freshwater sea,” by French explorers. Huron is the second largest Great Lake by surface area.

It later got its name from the Wyandot Indians, or Huron people who lived along its shores. It forms the eastern outline of Michigan's "Mitten," including the distinctive "Thumb" which is dotted with port towns and shelters Saginaw Bay.

Hydrologically, it comprises the easterly portion of Lake Michigan–Huron, having the same surface elevation as Lake Michigan, to which it is connected by the 5-mile-wide, 20-fathom-deep (120 ft) Straits of Mackinac. Michigan and Huron are actually two halves of one body of water, according to the University of Wisconsin. It is shared on the north and east by the Canadian province of Ontario and on the south and west by the U.S. state of Michigan.

The northern parts of the lake include the North Channel and Georgian Bay. Saginaw Bay is located in the southwest corner of the lake. The main inlet is the St. Marys River, and the main outlet is the St. Clair River.

On November 9, 1913, the Great Lakes Storm of 1913 in Lake Huron sank 10 ships, and more than 20 were driven ashore. The storm, which raged for 16 hours, killed 235 seamen.

View of rocky shore of Lake Huron from east of Port Dolomite, Michigan, in the upper peninsula.

Lake Erie

It is the southernmost, shallowest, and smallest by volume of the Great Lakes and therefore also has the shortest average water residence time. The name was derived from erielhonan, the Iroquoian word for "long tail," which describes its shape. It is the fourth largest of the Great Lakes when measured in surface area (Ontario is the smallest).

Situated on the International Boundary between Canada and the United States, Lake Erie's northern shore is the Canadian province of Ontario, specifically the Ontario Peninsula, with the U.S. states of Michigan, Ohio, Pennsylvania, and New York on its western, southern, and eastern shores. These jurisdictions divide the surface area of the lake with water boundaries.

During the Prohibition years from 1919 to 1933, a "great deal of alcohol crossed Erie" along with "mobster corpses" dumped into the Detroit River which sometimes washed up on the beaches of Pelee Island. Notable rum runners included Thomas Joseph McGinty and the Purple Gang. The Coast Guard attempted to interdict the Canadian liquor with its Rum Patrol, and a casino operated on Middle Island.

During the 20th century, commercial fishing was prevalent but so was the boom in manufacturing industry around the lake, and often rivers and streams were used as sewers to flush untreated sewage which ended up in the lake. Sometimes poorly constructed sanitary systems meant that when old pipes broke, raw sewage would spill directly into the Cuyahoga River and into the lake. A report in Time magazine in 1969 described the lake as a "gigantic cesspool" since only three of 62 beaches were rated "completely safe for swimming".

Lake-effect snow makes Buffalo and Erie the eleventh and thirteenth snowiest cities in the entire United Since winds blow primarily west to east along the main axis of the lake, lake-effect snowstorms are more pronounced on the eastern parts of the lake. Buffalo typically gets 95 inches of snow each winter and sometimes ten feet of snow; the snowiest city is Syracuse, New York, which can receive heavy snowfall from both the lake effect process and large coastal cyclones. A storm around Christmas in 2001 pounded Buffalo with 7 feet of snow.

Lake Erie in Winter

Lake Erie is known for seiches, especially when strong winds blow from southwest to northeast. Seiches are typically caused when strong winds and rapid changes in atmospheric pressure push water from one end of a body of water to the other. When the wind stops, the water rebounds to the other side of the enclosed area. The water then continues to oscillate back and forth for hours or even days. In a similar fashion, earthquakes, tsunamis, or severe storm fronts may also cause seiches along ocean shelves and ocean harbors.

In 1844, a 22-foot seiche breached a 14-foot-high sea wall killing 78 people and damming the ice to the extent that Niagara Falls temporarily stopped flowing. As recently as 2008, strong winds created waves 12 to 16 feet high in Lake Erie, leading to flooding near Buffalo, New York. Lake Pontchartrain, Louisiana, is also known to routinely form small seiches after the passage of afternoon squall lines during summer months.

Far beneath the surface of Lake Erie, almost 1,800 feet below the bottom of the lake, salt mines continue to produce salt for the world above. Whiskey Island's Salt Mine is a 12 square-mile mine beneath Lake Erie (65 feet deep). The salt mine is accessed by a four-minute elevator ride from Whiskey Island in Cleveland. It has a series of tunnels and airlocks that regulate the air pressure and oxygen supply for the workers. During an average winter, the mine will produce approximately 4 million tons of rock salt.

The mines are held up by pillars of salt that are carefully calculated by size and number to hold up the mines and the entire lake above!

These salt mines were developed thousands of years ago when the basin was a shallow sea and dried up, leaving the salt behind.

Adding to the lore of the Great Lakes is the monster, the myth, the legend – Bessie. Reported in sightings as early as 1817, South Bay Bessie is reported to be thirty to forty feet long and serpent-like, with a dog-shaped head and pointy tail. A respected and beloved local legend, this creature has spawned namesakes in the Great Lakes area. An artist created a unique variety of lake art in a wood and plaster sculpture known as Lemmy (Lake Erie Monster), and the minor league hockey team, the Cleveland Monsters, are named after Bessie. Sightings of the monster occurred as recently as 1993, which could cement the legend of Bessie as a fun fact rather than a myth about the Great Lakes.

Bessie the sea monster

Lake Ontario

Lake Ontario is bounded on the north, west, and southwest by the Canadian province of Ontario, and on the south and east by the U.S. state of New York. The Canada–United States border spans the center of the lake. The Canadian cities of Hamilton, Kingston, Mississauga, and Toronto are located on the lake's northern shorelines, while the American city of Rochester is located on the south shore. This lake is the smallest of the Great Lakes when measured in surface area.

In the Huron language, the name Ontarí'io means "lake of shining water”. Its primary inlet is the Niagara River from Lake Erie. The last in the Great Lakes chain, Lake Ontario serves as the outlet to the Atlantic Ocean via the Saint Lawrence River, comprising the eastern end of the Saint Lawrence Seaway. The Long Sault control dam, primarily along with the Moses-Saunders Power Dam regulates the water level of the lake.

During the end of the last ice age when the ice receded from the St. Lawrence valley, the outlet was below sea level, and for a short time, the lake became a bay of the Atlantic Ocean, in association with the Champlain Sea. Gradually the land rebounded from the release of the weight of about 6,500 feet of ice that had been stacked on it. It is still rebounding about 12 inches per century in the St. Lawrence area. Since the ice receded from the area last, the most rapid rebound still occurs there. This means the lake bed is gradually tilting southward, inundating the south shore and turning river valleys into bays. The tilting amplifies the shoreline erosion on the south shore, causing loss to property owners.

As of 2012, nearly 50 people have successfully swam across the lake. The first person who accomplished the feat was a Canadian long distance swimmer Marilyn Bell, who did it in 1954 at age 16. Toronto's Marilyn Bell Park is named in her honor. The park opened in 1984 and is east of the spot where Bell completed her swim.

In 1974, Diana Nyad became the first person who swam across the lake against the current (from north to south). On August 28, 2007, 14-year-old Natalie Lambert from Kingston, Ontario, made the swim, leaving Sackets Harbor, New York, and reaching Kingston's Confederation basin less than 24 hours after she entered the lake. On August 19, 2012, 14-year-old Annaleise Carr became the youngest person to swim across the lake. She completed the 32-mile crossing from Niagara-on-the-Lake to Marilyn Bell Park in just under 27 hours.