Mary Island State Park

About

Mary Island State Park offers a true island camping experience in the heart of the St. Lawrence River's Thousand Islands region. The 12-acre park features steep, rocky terrain covered with dense forest, creating a secluded wilderness atmosphere just miles from the mainland. Each of the 12 waterfront campsites is strategically placed to maximize privacy and provide spectacular views of either the Canadian shore or the busy international shipping channel. Access to Mary Island requires a minimum 14-foot motorized boat, with the closest launch point at Keewaydin State Park, approximately 2 miles across the water. Boat rentals are available at both Keewaydin State Park Marina and Wellesley Island State Park Marina for those without their own vessel. Once on the island, campers can explore several foot trails, fish the surrounding waters, or simply enjoy the peaceful isolation. Despite its remote location, the park provides essential amenities including hot showers, restrooms, and water fill-up stations. Boats can be beached or moored near campsites. The campground operates seasonally from late May through early September, with reservations available up to 9 months in advance through ReserveAmerica.

Directions

Access is by boat only from Keewaydin State Park, approximately 2 miles across the water. A minimum 14-foot motorized boat is required. Boat rentals are available at Keewaydin State Park Marina or Wellesley Island State Park Marina.