KAYAKERS COME to this roadless, carless Lake Superior island for its rocky shoreline; fishermen and canoeists, for its 22 inland lakes; backpackers, for its wooded basaltic ridges populated by moose and timber wolves; and hermits, because in its entire season Isle Royale sees 40,000 fewer humans than Great Smoky Mountains gets on an average July day. A savvy and intrepid handful of park trailblazers know how to really get lost here: Venture below the lake's forbidding surface for SHIPWRECK DIVING. Ten major vessels have come to rest in park waters in the last 125 years, and the same frigid 40-degree water that forces divers to don drysuits has drastically slowed the wrecks' decomposition. Visibility is so good you can survey a ship's exterior 40 feet down without a light. The shallower remains are most popular, such as theAmerica, a package freighter that sank in 1928 and whose bow lies just a few feet below the surface. Others sit farther down; the Kamloops, a Canadian freighter that took 50 years to locate after it succumbed to a blizzard in 1927, lies between 175 and 260 feet under. Most divers join one of two Park Service-sanctioned dive-charter operatorsSuperior Trips (651-635-6438, www.superiortrips.com) and RLT Divers Inc. (507-238-4671, www.rltdivers.com)and spend a week diving and camping in any of the park's 36 designated campgrounds. Isle Royale is only open mid-April through October; ferry rides from Grand Portage, Minnesota, or Michigan's Upper Peninsula take three to seven hours.
WHEN TO GO: The number of visitorsas well as blackflies and mosquitoessubsides in the shoulder seasons, before June and after August, if you don't mind risking more fickle weather and rougher chop on Lake Superior.
ANNUAL VISITORS: 15,180. (High: August, 5,664. Low: October, 112.)
MORE CHOICE ADVENTURE: HIKE a portion of the 165-mile network of trails, such as the 42-mile Greenstone Ridge or the rougher 29-mile Minong Ridge. Each traverses the island from northeast, over steep bedrock ridges, to southwest, where you'll find thick forests of birch, maple, and other northern hardwoods. The Minong's marshy wetlands are prime moose turf in the summer. Come nightfall, listen for the spine-tingling sound of wolves howling.
HEADLAMP READING: Shipwrecks of Isle Royale National Park: The Archaeological Survey, by Daniel Lenihan, et al.; Isle Royale National Park: Foot Trails and Water Routes, by Jim DuFresne
LOCAL SPECIALTY: At the Harbor Haus in Copper Harbor, Michigan, the picture windows overlook Lake Superior, the walls are adorned with deerskins and beer steins, the German-leaning kitchen serves up lake-caught whitefish, venison sausage, and desserts made with local thimbleberries, and the table-waiting frauleins duck out onto the back patio for a Rockette-style kick line to greet the ferry returning from Isle Royale.
INSIDE SCOOP: The park is a remarkable case study of the peculiar cycles of island biogeography. In the mid-19th century, it harbored populations of caribou, coyotes, chipmunks, and redbacked volesnone of which exist there nowbut not a single moose or wolf. Prevailing speculation suggests that the moose swam over around 1900, and that wolves arrived in the winter of 1949-1950, the last time ice formed an unbroken bridge to the mainland.
PARK HEADQUARTERS: 906-482-0984, www.nps.gov/isro