Half of 113 square mile Isle au Haut is privately owned, but the other half is a part of Acadia National Park and boasts eighteen miles of trails. The Isle au Haut Trace is a challenge to link all of these trails in a single push, making a complete loop back to your origin point, without the use of vehicles. The relevant trails are blue-blazed and are predominantly loamy singletrack, with a few rocky beach miles and a touch of scrambling.