Isle Royale National Park

Isle Royale National Park, in northern Michigan, was authorized in 1931 and designated a Biosphere Reserve in 1980. The 571,790-acre park includes Isle Royale, the largest island in Lake Superior, as well as 50 smaller islands. The main island, 45 miles long and 8 miles at its widest, contains pre-Columbian copper mines. Accessible only by boat, its wildlife consists only of animals that can fly, swim, or drift across the 15 miles of open water that separates it from the nearest mainland, Canada. A wide variety of northern wildflowers grows in the forests of spruce, birch, fir, and cedar.