Isle Royale National Park is a roadless wilderness island in the northwest corner of Lake Superior, closer to the Canadian shore than to Michigan. It is one of the least-visited national parks in the lower 48, and that isolation is the point — no cars, no roads, no cell service. You get there by ferry or seaplane from Houghton or Copper Harbor, and once you arrive, you walk.
The island is famous for the long-running wolf-moose study, one of the longest predator-prey studies in history. Wolves were reintroduced here after nearly dying out, and moose are everywhere — you will almost certainly see them on the trails. The backcountry hiking is superb: ridgeline trails with views over the vast lake, inland lakes for fishing, and sheltered harbours where kayakers can camp. Rock Harbor on the east end has a lodge and basic services; the rest of the island is backcountry. The park is open roughly mid-April through October; winter access requires special arrangements.