Isle Royale
Credit: Carl TerHaar / Getty Images

Michigan's Isle Royale isn't easy to get to – visitors must arrive by boat or seaplane – but it's worth the effort. Located in the northwest corner of Lake Superior, the untamed island is known for wild wolves and moose, but that doesn’t stop visitors from spending roughly three days at the park on average. It has two developed areas, Windigo and Rock Harbor, which have small stores, showers, boat docks, and 36 wilderness campgrounds that typically include wooden shelters and tent areas. 

Don't Miss: The Rock of Ages Lighthouse, just 3.5 miles west of Isle Royale, has six above-water decks for fog signal equipment and living quarters that include an office, common room, kitchen, and sleeping area.