The Thousand Islands Parkway (often written as 1000 Islands Parkway) is a scenic parkway in the Canadian province of Ontario. It extends easterly from an interchange with Highway 401 in Gananoque for approximately 40 kilometres (25 mi) to rejoin Highway 401 near the community of Butternut Bay, west of Brockville. The parkway follows the north shore of the St. Lawrence River, and was formerly designated Highway 2S (S for Scenic) until 1970. It passes through the communities of Gray's Beach, Halsteads Bay, Ivy Lea, Darlingside, Rockport, Narrows, La Rue Mills and Mallorytown Landing, as well as providing access to the three inland properties of the Thousand Islands National Park. Highway 137, which meets the parkway near its midpoint, provides access to the Interstate 81 in New York via the