Isle Royale is the largest island in Lake Superior, all of which is a national park. Isle Royale is over 50 miles (80 km) in length and is accompanied by multiple smaller islands, particularly on its northeast end. The island is a part of the state of Michigan and was once the site of a fishing industry and resort community. Isle Royale National Park was established in 1940. It is a small national park at 572,000 acres, although only 134,000 acres is above water. It is known for its wolf and moose populations which are studied by scientists investigating predator-prey relationships in a closed envirnoment. There are usually around 25 wolves and 1000 moose on the island but the numbers change greatly year to year. It is accessible by ferry during the summer months from Grand Portage, Minnesota and Houghton and Copper Harbor in Michigan.

Isle Royale greenstone, (chlorastrolite, a form of Pumpellyite) is found here as well as on the Upper Penninsula of Michigan. It is the official Michigan state gemstone. The Greenstone Ridge is a high ridge in the center of the island and carries the longest trail in the park, the Greenstone Ridge trail, which runs 40 miles from one end of the island to the other. This is generally done as a 4 or 5 day hike. A boat shuttle carries hikers back to the start.

The parks two developed areas are Windigo, in the southwest with a campstore, showers and boat dock, and Rock Harbor in the northwest with campstore, showers, restaurant, lodge, campground and boat dock.