Around rock harbor
If you're spending the night at Rock Harbor campground, staying at Rock Harbor Lodge, or a day-tripper from Michigan, there are several ways to spend your day.
Passage Island
Guided tours, organized activities, and boat expeditions are offered; check at the lodge to see what's on the schedule. The boat trips can take you to some of the more interesting spots along the southeast end of the island, such as Passage Island and its lighthouse a few miles into Lake Superior, and several of the sites mentioned below for self-exploration. The lodge also schedules nightly informational programs.
Tobin Harbor
Rent a canoe and paddle Tobin Harbor, a long, sheltered inlet on the north side of the narrow peninsula the lodge and ranger station are on. This lightly-developed "historic district" was a popular site for little cottages a century ago mostly out near the Lake, but aside from the periodic floatplane landing/take-off, it's generally more quiet than "hectic" Rock Harbor, and also provides a shortcut to the trail leading to the breathtaking view from Lookout Louise up on the Greenstone Ridge. Sample canoe rental rate: $18 for six hours.
Rock Harbor
Rent a canoe and paddle Rock Harbor. You can work your way along the shoreline of the harbor, or explore the several barrier islands that shelter it from Lake Superior. Raspberry Island turn slightly to the left when you leave Snug Harbor has a trail with closely-placed examples of several of Isle Royale's environments including some short but difficult sections of trail. Note that Rock Harbor offers little shelter from windy weather, paddling between the barrier islands can expose you to Lake Superior waves, and on the lakeward side of the islands crashing waves and swells can easily tip or swamp a canoe. You'll also have to be prepared for periodic wakes from motorboats zipping the length of the harbor for one reason or another.
outboard motor
Rent a boat with an outboard motor and go fishing in Rock Harbor or explore farther afield. East Caribou and Mott Islands joined by a footbridge are home to the sometimes noisy park headquarters, but also have a 2.5-mile trail that takes you to the Lake Superior shore on the side away from Rock Harbor. Edisen Fishery and Rock Harbor Lighthouse both well-preserved 19th century relics are across from Daisy Farm campground at the mouth of Moskey Basin. Just a little west of Edisen is another former fishery which is the summer residence of wolf/moose researchers Candy and Rolf Peterson, who have a huge collection of moose bones in their yard look for the Norwegian flag.
Stoll Trail
To spend a few hours on your feet, hike the Stoll Trail east out to rocky Scoville Point, passing a pair of old copper-mining pits along the way. Or take the Rock Harbor Trail a couple miles west to Suzy's Cave, a "secret passage" formed by the lake when it was much higher, and return on the Tobin Harbor Trail or vice versa. The Tobin Harbor and Stoll Trails are the least difficult, but both involve some tricky footsteps Stoll especially and steep stretches of trail Tobin Harbor especially.
Mt. Franklin
For a longer hike, trek up onto the Greenstone Ridge to Mt. Franklin and back about 10 miles round-trip. For a vigorous day-long hike, continue west to Mt. Ojibway and return by way of the Daisy Farm and Rock Harbor Trails about 15 miles total. No water sources exist on the ridge proper, and it can reach the low-80s 25+ Celsius on summer afternoons at higher altitudes -- pack accordingly.
Around windigo
Those staying at Washington Creek campground or day-tripping from Minnesota have a few options as well.
nature trail
There are two self-guided nature trail loops at Windigo, one less than a mile, the other a little more than a mile.
Washington Harbor
Rent a canoe and explore sheltered Washington Harbor, and Grace Harbor at the edge of Lake Superior. These have plenty of shoreline, several islands, and the barely-underwater sunken cruise ship America to explore best reached by motorboat.
Wendigo Mine
The old Wendigo Mine ruins not a typo; 19th-century spellings are sometimes inconsistent are a couple miles inland on the East Huginnin Cove Trail.
Feldtmann Ridge Trail
Hiking the first 2 miles of the Feldtmann Ridge Trail and back provides good views of Washington Harbor, including a short trail leading to a good overlook. Continuing farther offers less scenic views, but nice woodland hiking.
Huginnin Cove
The 9-mile trail loop to Huginnin Cove and back is too far for a day-visitor to the island, but can be done in 4-6 hours if you're staying at Washington Creek campground, especially if you leave your gear behind. It has some difficult, steep stretches of trail.
Minong Ridge
Similarly, there's an overlook of the Minong Ridge a little more than 4 miles along that trail.
Fishing is a popular activity, which you can do from motorboats in the waters surrounding Isle Royale, or from canoes in its inland lakes many of which are both secluded and teeming with fish. Angling in the waters of Lake Superior including bays requires a Michigan fishing license, which you can buy at either port's ranger station. Hunting is not permitted.
A number of ships have met disaster on the rocks and islets around Isle Royale, making the surrounding waters fairly popular with shipwreck divers.
backcountry
Be
Although most people come to Isle Royale specifically to hike the trails or to paddle the lakes, and to enjoy the physical challenge of it, keep in mind that there's no prize for putting in the most miles, and no penalty for spending a day or two in one area. It's too easy to come away from the island remembering little except the view of your boots on the trail or the bow of your canoe in front of you. Allow yourself some time without a pack on your back or a paddle in your hands, and just be on the island.
If you have more than a few hours to spend on the island, head off into the backcountry. The National Geographic Society publishes a very good waterproof topographic map of Isle Royale with campgrounds and trails marked, and mileages for both land and water routes between sites at $10. The book Isle Royale National Park: Foot Trails & Water Routes by Jim DuFresne ISBN 0898867924 is an excellent resource, describing the regions and routes in experienced detail. Both are available at the information offices on the island, but are most useful for planning your trip before arrival.
The interconnected trails and the portage-linked lakes and bays make it easy for you to devise your own itinerary among the island's campgrounds. But there are some common routes that begin and end at the ports, or at docks accessible by ferry or water taxi: