10 Facts That Make Isle Royale National Park Unique

Sunrise at Rock Harbor
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Surrounded by Lake Superior in the state of Michigan, Isle Royale National Park is a rugged, remote site that consists of Isle Royale and hundreds of smaller islands adjacent to it. It covers 894 square miles, with 209 square miles of land and 658 square miles of water.

Indigenous peoples call the island “Minong,” which translated to English means “a good place to get copper.” In the 1840s, Euro-American miners moved in and established copper mines to harness the resource.

Isle Royale National Park was established in 1940 and designated a wilderness area in 1976 to prevent further development. In 1980, it was declared a UNESCO International Biosphere Reserve and in 2019 it was officially listed as Minong Traditional Cultural Property on the National Registry of Historic Places.

The park is home to a variety of creatures, including wolves, beavers, foxes, snowshoe hares, rodents, and moose. The area has become one of the most significant study sites for predator-prey interactions and its wolves are among the most famous wild animals in the world.

Isle Royale National Park Contains Hundreds of Islands

Lookout Louse
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Isle Royale National Park is located in the northwestern portion of Lake Superior. It’s a remote island archipelago that consists of one large island and over 450 smaller islands that surround it.

Long and thin, the large island (Isle Royale) is 45 miles in length and about 9 miles wide at its widest point. Along with Isle Royale and its surrounding islands, Isle Royale National Park contains all submerged lands within a few miles of the islands.

Not Many Animals Live There

Because the islands of Isle Royale National Park are so rugged and isolated, only 19 mammal species are able to live there. On the surrounding mainland, there are over 40 mammal species.

It’s the Location of a Long-Running Wolf Study

A grey wolf standing on a rock in a forest.

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Often referred to as the timber wolf, the gray wolf has been the top predator of Isle Royale National Park since it arrived in the late 1940s. Experts believe they arrived by crossing an ice bridge that formed between the island and the Canadian mainland.

Scientists have studied the predator-prey relationship between wolves and moose on the island for decades to better understand the ecology of predation and what that can teach us about our relationship with nature. While wolves help stabilize the moose population by preying on them, a large moose population supports the wolves during winter hunting. The ecological study of wolves on Isle Royale is the longest-running large mammal predator-prey study on earth.

It Used to Be Covered in Ice

Isle Royale’s geographical history began about 1.2 billion years ago when a rift opened the earth’s crust, which produced rocks that form the bedrock of the park today. 

Glaciers overran the area and formed its distinct ridges, valleys, and parallel islands. The latest ice-advanced left a thin mantle of glacial deposits that range from a few inches deep to four feet deep. And as the glaciers retreated, meltwaters created the many distinct lakes seen on the islands.

There Are a Few Developed Areas

Most of Isle Royale National Park is a Designated Natural Wilderness area, which protects it from development. However, there are two developed areas within the park: Windigo and Rock Harbor.

Windigo is located at the southwest end of Isle Royale and is a docking site for the ferries that bring visitors from Minnesota. The area has showers, campsites, rustic cabins, and a modest general store.

Rock Harbor is also a ferry docking site, but for ferries from Michigan. It’s located on the south side of the northeast end of the island and has similar amenities to Windigo with the addition of a restaurant, lodge, and boat dock (no cabins, though).

Various Shrubs Are Common There

Thimbleberry plants in nature.

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Perhaps the most abundant Isle Royale shrub is the thimbleberry. The plants are characterized by maple-like leaves, white flowers, and juicy red berries. The fruits are edible, but some visitors find them too tart. Fortunately, there are sweeter blueberries, raspberries, and sugar plums around.

In rocky areas, there are plenty of bearberry, prickly rose, juniper, and mountain ash growing. Leatherleaf, bog laurel, bog rosemary, labrador tea, tag alder, and sweet gale all grow in Isle Royale’s more boggy areas and wetlands.

If you do plan to sample berries on the island, make sure you know exactly what you’re eating, as there are some poisonous fruits and plants present.

It’s One of the Least Visited National Parks in the US

Isle Royale is Michigan’s only national park and is one of the country's least-visited national parks. In 2018, over 25,000 people visited the site. Larger, more popular parks see many more visitors in a year. For example, Yellowstone National Park in Wyoming, which is nearly four times the size of Isle Royale National Park, saw over 4 million visitors in 2018.

It Closes for the Winter

The park is open each year from April 16 through October 31, closing from November 1 through April 15 because of extreme winter weather that passes through. It’s the only American national park to close entirely for the winter, which likely contributes to its relatively low number of annual visitors.

In the spring and summer months, visitors can access the park by ferries, floatplanes, and passenger ships that come from both Michigan and Minnesota. It’s also accessible by private boat.

It’s Home to Many Bird Species

A family of Sandill Cranes walking through a marsh.

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Bird species including the sandhill crane, great blue heron, downy woodpecker, snow bunting, double-breasted cormorant, winter wren, and ovenbird visit Isle Royale National Park. Currently, there are 82 bird species that frequent the area.

Historical records show changes in species and populations over the past century and demonstrate that habitats have fluctuated. Some habitats have changed due to human actions, like fires set to reveal copper sources, but others have changed due to the natural progression of the forest.

Scientists Continuously Monitor the Park

A person kayaking along a rocky shore.

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A network of biologists with the National Park Service and the Great Lakes Inventory and Monitoring Network monitor Isle Royale to look for trends in the health of inland lakes, forest vegetation, and animal populations. Monitoring results inform park management to better protect the island’s natural systems.