The far edge of this 21-island archipelago is harder to reach than hubs like Stockton Island, but the payoff—empty campsites, little-known sea caves—beats camping amid a slew of families. Reserve campsite permits for Outer and Devil’s Islands a month in advance ($10 per night; 715-779-3397), and rent boats and gear at Living Adventures in Bayfield, which also guides trips (rentals from $32). Make the 18-mile paddle to Devil’s Island and spend the next morning exploring the park’s most extensive sea-cave system—a portico of red striped columns and galleries along the island’s north rim—before the wind flushes them with afternoon waves.
On day two, make your way past red sandstone boulders that litter the shoreline to Outer Island, which has numerous small waterfalls and a 140-year-old lighthouse to explore. On day three, head inland to Oak Island, where you can stretch your legs on 11 miles of trail. Grab campsite A, which abuts a long sandspit beach. As you paddle back to Bayfield on your last day, check out the 100-year-old wrecks of the Fedora, Ottawa, and Coffinberry, each lurking just below the surface.