The largest island in Lake Superior, Isle Royale is 45 miles long and 9 miles across at its widest point. It lies 56 miles from the Upper Peninsula shore and 20 miles from the Canadian shore.
Visited by the French explorer Étienne Brűlé in 1622, its early name was Minong (Chippewa Indian for "good high place"); it was renamed by French Jesuit missionaries to honour their royal patrons.
Its streams and inland lakes contain pike, perch, and other game fish. Coniferous and deciduous forests provide an outstanding example of forest transition; many species of wildflowers, ferns, lichens, mosses, and fungi grow undisturbed. Moose and fur-bearing animals are common, and a small population of timber wolves lives on the island. There are more than 200 kinds of birds, including herring gulls and warblers.
According to radioactive-carbon tests, prehistoric copper-mining pits date back nearly 4,000 years. A greenstone (chlorastrolite) from Isle Royale was adopted as the state gem in 1972.
Travel is possible only on foot or by canoe. Ferry service from the mainland is available from Houghton and Copper Harbor, or from Grand Portage, Minn. Isle Royale, with its surrounding islets and numerous rocks, was established as a national park in 1931.