About Isle Royale National Park

Isle Royale National Park, Michigan, was authorized by Congress and approved by President Herbert Hoover on March 3, 1931. The park was officially established by President Franklin Roosevelt on April 3, 1940. Isle Royale National Park is in the northwestern section of Lake Superior comprising 571,790 acres, within 14 miles of the Ontario (Canada) shoreline, 20 miles of Minnesota shoreline, and approximately 45 miles from Michigan’s Upper Peninsula.

The park includes the primary large island known as “Isle Royale,” and more than 400 smaller islands that together form a complex, forested archipelago surrounded by the deep, cold waters of the largest North American Great Lake. Within the designated boundary, more than 75% of the total park area is submerged. There are no contemporary roads on the island and the park is currently only accessible by ferry, seaplane, or private boat. A portion of the park’s northern boundary within Lake Superior abuts the international border between the United States and Canada.

Since establishment, the park has been managed with a focus on backcountry-based recreation in concert with protection of natural and cultural resources. Under provisions of the Wilderness Act of 1964, 132,018 acres of the park’s surface land base, or 99% of the total 133,788 land acres, were designated as wilderness or potential wilderness on October 20, 1976. Isle Royale is one of 13 national park system units and 23 federal wilderness areas within the Lake Superior Region in the states of Michigan, Minnesota, and Wisconsin. The park was designated an International Biosphere Reserve by the United Nations in November 1980.

The rocks of the Isle Royale archipelago exhibit more than one billion years of geologic processes, including successive volcanism, sedimentation, uplift, and erosion. Isle Royale contains minerals such as copper, greenstone, datolite, and agate.

This heavily forested archipelago is in a zone of transition between two major North American ecosystems or biomes—the boreal coniferous forest and northern hardwood forest. Boreal forest vegetation dominates the northeastern part of the island. Balsam fir and white spruce, interspersed with pockets of paper birch and quaking aspen comprise the so-called “climax” of the boreal coniferous forest. Boreal forest vegetation is strongly influenced by lake effect climate and shallow soils. Northern hardwoods are more dominant on Isle Royale’s southwestern portion where soils are deeper and inland areas are less affected by Lake Superior influences than the exposed ridges and peninsulas of the northeastern end. Sugar maple and yellow birch is a dominant community on the island that is more stable and less disturbance-prone than the boreal forest. Ridges are occupied by small, open stands of northern red oak, white pine, jack pine, spruce, red maple, or occasionally red pine. In swamps and wetland forests of the park, black spruce and white cedar are dominant with the occasional occurrence of nondominant eastern tamarack. Treeless areas on the ridges support patchy grasses and shrubs, primarily common serviceberry, honeysuckle, hazelnut, and blueberry. These areas, prone to lightning because of their exposure, have burned frequently, leaving little organic soil and thwarting forest encroachment. Bogs and beaver meadows are dominated by dense stands of sedges, rushes, grasses, and shrubs such as alder that grow along the marginal edges of these wetland communities.

The climate of the park, strongly affected by Lake Superior, is characterized by short, cool summers and long, cold winters. Due to the moderating influence of the lake, summers are cooler and winters are warmer than on the nearby mainland. Fog is frequent near the lakeshore, especially in the spring.

Aquatic habitats account for more than 75% of Isle Royale National Park and encompass a wide spectrum of environments from the cold, deep waters of Lake Superior to inland streams, beaver ponds, lakes, marshes, swamps, wet meadows, and bogs. The park includes 438,008 acres of Lake Superior, in addition to about 200 inland lakes and ponds totaling some 9,050 acres. There are approximately 158 linear miles of perennial streams on Isle Royale. Isle Royale’s Lake Superior and inland lakes fisheries may well be the most nationally significant natural resources of the park; 61 species are known to be present. The park’s lake trout population is acknowledged as the best example of a rehabilitated lake trout stock in all of Lake Superior. The Isle Royale population of the extremely rare coaster brook trout is one of only three known reproducing populations in US waters. In fact, eggs from this population have been used by the US Fish and Wildlife Service in efforts to reestablish the coaster brook trout elsewhere in Lake Superior.

Isle Royale’s biodiversity (except for birds) is generally lower than that of the mainland because the islands’ isolation has restricted migration of terrestrial organisms from outside populations. For example, there are approximately 19 species of mammals documented on Isle Royale, far fewer than the number of mammals on the adjacent mainland. In addition, the limited land area of the archipelago probably impedes the long-term survival of viable populations of larger organisms with larger home ranges or territories. Wolf and moose populations, together on the island only since the late 1940s, have become a classic study in predator/prey relationships. For many people these wildlife populations and their conservation are the essence of Isle Royale’s wilderness character.

Evidence of human use, activity, and habitation can be found throughout Isle Royale and in the surrounding waters. As a rich source of fish, wildlife, plants, and minerals, Isle Royale has attracted human visitors and residents for millennia. Cultural resources ranging from lithic scatters of chipped stone to lighthouses reveal a rich history of human use spanning from Archaic times (ca. 3000 BC) to the present. Stone tools, mining pits, shipwrecks, vernacular boats, fishing camps, summer cabins, domestic flowers, and medicinal plants are all part of the cultural resources of the island. Many sites and resources still exist from precontact and historic use of the island, including periods of use by American Indians, voyageurs, and fur traders, and from extensive commercial fishing and mining, Lake Superior shipping, and vacationing and resort development. These cultural resources are categorized as archeological sites, historic structures, cultural objects, cultural landscapes, and ethnographic resources.

The first evidence of human use of Isle Royale was left by Archaic period aboriginal copper miners. Shallow pits remain throughout the island as testimony to the special purity of Isle Royale’s copper deposits. Native groups also came to harvest the island’s other natural resources through hunting, fishing, and gathering plants and berries. Three phases of historic copper mining punctuated the 19th century history of the island. Coming thousands of years after prehistoric miners, historic entrepreneurs often mined the same sites that had attracted native peoples. Success was limited because of the high cost of operation at Isle Royale. Initial profits ended when pure copper veins pinched out and inevitably all of the copper mining companies went out of business.

Abundant lake trout, whitefish, and herring populations supported a century of commercial fishing. More than 100 fishing families were based on the island at the peak of the industry in the early 1900s. However, fish populations declined severely with the arrival of the lamprey and the concurrent pressures of commercial fishing, which took their combined toll by the 1960s. Even though fish populations rebounded in later decades, the establishment of Isle Royale National Park meant an end to widespread commercial fishing operations therein.

Around the turn of the 20th century, tourism began to blossom at Isle Royale. The isolation and rugged nature of the area that draws visitors today appealed to Americans a century ago, as they sought escape from hot, crowded and dirty cities, and the torment of hay fever. Lodges and resorts opened at Washington Island, Belle Isle, Tobin Harbor, and Rock Harbor. Resort tourism thrived in the first three decades of the 20th century and helped give rise to the idea of making a “great island” national park.

The Civilian Conservation Corps (CCC) played an important role in the construction of trails and facilities on the island. CCC camps were set up at Siskiwit Bay, Rock Harbor (Daisy Farm), and Washington Harbor. Between 1935 and 1941, they were an important presence on the island and were instrumental in fighting the 1936 fire that consumed 20% of the island’s forests.

As an island archipelago in the world’s largest body of fresh water, Isle Royale has a rich maritime history. The story of Isle Royale is the story of fishing boats, passenger liners, and commercial shipping. To steer ships through treacherous reefs, four lighthouses were established at Isle Royale. The island could be both a safe haven during storms and a deadly obstacle that claimed numerous vessels over the years. Boat traffic brought occasional tragedy and Isle Royale is well known for its many shipwrecks.

Source: Foundation Document – Isle Royale National Park

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