King's Highway 137, commonly referred to as Highway 137, is a provincially maintained highway in the Canadian province of Ontario that connects the northern end of Interstate 81 in the U.S. state of New York with Highway 401 via the Canadian span of the Thousand Islands Bridge. While this road connected to the international bridge when it opened in August 1938, it was not designated as a King's Highway until 1965. Highway 137 passes through a portion of the Canadian Shield, a geographic feature which aided construction of the three Canadian spans of the Thousand Islands Bridge. These bridges, all of different designs, travel 538 m (1,765 ft) across the Saint Lawrence River. Highway 137 is 4.3 km (2.7 mi) in length and is located entirely within the United Counties of Leeds and Grenville.

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 Thousand Islands Bridge.