Which national park is located in Michigan's Upper Peninsula?

Isle Royale National Park is indeed located in the Upper Peninsula of Michigan. It is a remote and unique island park situated in Lake Superior, making it accessible primarily by boat or seaplane. The park is renowned for its rugged natural beauty, diverse ecosystems, and its population of moose and wolves, which have become subjects of ecological study. Twin to the natural landscapes, the isolation of Isle Royale contributes to its pristine condition, attracting hikers, backpackers, and nature enthusiasts seeking an unspoiled wilderness experience.

In contrast, Pictured Rocks National Lakeshore, while situated in the same region of Michigan, is located along the southern shore of Lake Superior but is not technically a national park; it's a lakeshore unit that offers stunning landscapes and dramatic cliffs. Sleeping Bear Dunes National Lakeshore is found in the Lower Peninsula, characterized by its expansive sand dunes along Lake Michigan. Porcupine Mountains Wilderness State Park, another beautiful natural area, is also located in the Upper Peninsula, but it is a state park and not a national park. Thus, Isle Royale National Park is the only correct choice given the criteria of being a national park in Michigan's Upper Peninsula.