Fun Facts About the Great Lakes

There is not much you can tell a Michigander about the Great Lakes that they do not already know by heart. They can name all five in order of size, recite the depth of the one they grew up on, and tell you exactly which beach has the best sunset. The lakes started as a mile-thick sheet of ice that ground the land into deep basins, then filled them with meltwater as it retreated. What the glaciers left behind is the largest freshwater system on the planet, ringed by 4,530 miles of U.S. shoreline that doubles as a year-round playground. Here is a proper field guide to the water, the wrecks, the lighthouses, and the legends.

The largest freshwater system in the world

The Great Lakes cover roughly 95,000 square miles and hold about 20 percent of the world's surface fresh water, close to six quadrillion gallons. That basin supports more than 3,500 species of plants and animals, over 170 kinds of fish, and around 34 million people living on both sides of the U.S.-Canada border. Every lake pulls its weight in shipping, power, recreation, and tourism. What makes each one distinct is the shape of the bottom, which is exactly what a wood chart is built to show: each layer of birch is a real depth contour, stacked to reveal the true relief of the lakebed.

The five lakes, by the numbers

• Lake Superior is the largest freshwater lake on Earth, 82,000 square miles of it, dropping to 1,333 feet at its deepest. It averages about 36 degrees, so a summer swim still reads as a polar plunge.
• Lake Huron ranks second by surface area at 23,000 square miles and owns the longest shoreline of the five, 3,827 miles once you count every island. Its deepest point is 750 feet.
• Lake Michigan is third at 22,404 square miles and the only Great Lake held entirely inside the United States. It bottoms out at 923 feet and warms to a swimmable 74 degrees at the surface in high summer.
• Lake Erie is fourth by area at 25,667 square miles and the shallowest of the group, just 210 feet at its deepest, which is why it warms fast and freezes hard.
• Lake Ontario is the smallest by surface at 7,340 square miles, yet it holds four times the water of Erie thanks to a maximum depth of 802 feet. It sits at the foot of Niagara Falls.

Lake Michigan is the only one entirely in the U.S.

Four states share Lake Michigan's 1,400 miles of coast: Michigan, Illinois, Wisconsin, and Indiana. French traders once called it Lac du Chat. Today it is best known in Chicago for Lake Shore Drive, the run of sand and skyline past Lincoln Park, Soldier Field, and Navy Pier. Head north and the shoreline turns into dune country and beach towns: Traverse City, Muskegon, Grand Haven, each with its own pier, its own ice cream stand, and its own claim to the best sunset. If you want the city on your wall, the Chicago wood chart carves the harbor and lakefront in the same layered relief as the lake itself.

A sport fishing destination second only to Florida

About one million pounds of fish come out of the Great Lakes commercially, and for recreational anglers the region ranks second only to Florida. The variety is the draw: walleye, yellow perch, lake whitefish, brook trout, and lake sturgeon, plus salmon that were introduced decades ago and have thrived. Superior alone holds more than 80 species. The lake sturgeon is the giant of the basin, capable of reaching 200 pounds and living past a century, and active restoration work is bringing its numbers back. That is one fish story you do not want getting away.

Roughly 35,000 islands

Uneven glacial scouring left about 35,000 islands scattered across the basin, and Lake Huron claims more than 30,000 of them on its own. Chief among them is Manitoulin, the largest freshwater island in the world at 1,068 square miles, with roughly 12,600 year-round residents. Out on Superior, the Apostle Islands string along the Wisconsin coast, their historic lighthouses once guiding freighters through the maze toward the port at Bayfield. With no salt and no sharks, these islands offer some of the most inviting backcountry you can only reach by boat, floatplane, or ferry.

More than 200 working lighthouses

The Great Lakes still run over 200 active lighthouses along their 11,000-plus miles of shoreline. Many date to the early 1800s and were fitted with French-made lenses strong enough to throw light miles out over the water. A good number have gone automated, and a few, like Big Bay Point Lighthouse in the Upper Peninsula, now take overnight guests. Locals will tell you Big Bay is haunted, which only seems to help bookings. The lights were never decoration. They mark where the water goes shallow fast, and the layered depth on a wood chart shows exactly why a keeper's warning mattered.

Over 6,000 shipwrecks

The basin gives ships no natural harbor to run for when a storm rolls in, which is a large part of why more than 6,000 wrecks lie on the bottom, many never found. Lake Erie is thought to hold the most, around 2,000, preserved almost perfectly in cold fresh water that does not rot wood or rust steel the way the ocean does. Because Erie is so shallow, plenty of those wrecks sit within reach of snorkelers and glass-bottom boat tours. The cold that sank them is the same cold that keeps them looking, a century later, like they went down last season.

Salt mines beneath the lakes

Almost 2,000 feet under the floor of Lake Erie, working salt mines still pull out the mineral that keeps northern roads passable all winter. The salt was laid down hundreds of millions of years ago, when the basin was a shallow sea that dried and left its minerals behind. The chambers are held open by pillars of salt, their size and spacing carefully engineered to carry the weight of the rock and the entire lake overhead. It is one of the strangest facts about the region: a cathedral of salt working around the clock beneath all that water.

The mystery of the Michigan Triangle

Lake Michigan has its own answer to the Bermuda Triangle. The Michigan Triangle runs from Manitowoc, Wisconsin, across to Ludington, Michigan, and south to Benton Harbor. The stories started in 1891 with a schooner that vanished without leaving so much as a plank behind, and the area has since been blamed for unexplained accidents, missing crews, and the 1950 disappearance of a commercial airliner that was never recovered. A wood chart maps the depth and complexity of the bottom in that stretch in fine detail. What it cannot map is why the Triangle keeps its secrets.

Bessie, the resident sea monster

Every great body of water eventually gets a monster, and Lake Erie's is Bessie. Reported since 1817, South Bay Bessie is described as a serpent 30 to 40 feet long with a dog-shaped head and a pointed tail. The legend has real staying power: a local sculptor built a wood-and-plaster tribute named Lemmy (Lake Erie Monster), and Cleveland's minor league hockey team took the name Monsters in her honor. Sightings ran as recently as 1993, which is either a fun fact or a warning, depending on how you feel about swimming after dark.

See it all: the Circle Tour

If you want to meet every lake in one trip, the Great Lakes Circle Tour runs about 6,500 miles through eight states and a stretch of Ontario that will have you reaching for a passport. Drive it and the forests, dunes, and open water of Up North tend to stay with you long after you are home. That lasting pull is what a Great Lakes wood chart is for: every basin carved to its real depth, every shoreline true, so the water you keep coming back to has a place on the wall the rest of the year.

Ready to put your lake where you can see it? Browse the full Great Lakes collection, dig into our favorite Great Lakes wood maps, or find your home water among the Michigan charts.