Overview Duck Harbor campsites are reservable starting on April 1st at 10:00am ET. Duck Harbor Campground is located on Isle au Haut, a rugged island off the coast of Stonington, Maine. Remote and inaccessible to automobiles, Isle au Haut is linked to the mainland by mailboat. Recreation Isle au Haut offers excellent hiking. The remoteness of the island provides a quiet experience along primitive trails with many great views of rocky cliffs and coastal scenery. Bicycling is allowed but is very r