On the northern shore of the St. Lawrence, Highway 137 abruptly turns eastward, passing a road maintenance facility and the southbound toll booths before curving back northward as it widens into a divided highway at an interchange with the Thousand Islands Parkway. The final segment of the highway travels through forest before ending at a trumpet interchange with Highway 401 midway between Gananoque and Brockville. The geography surrounding the entire route features large rock outcroppings of the Frontenac Arch in the Canadian Shield through which the highway passes. The close proximity of bedrock to the surface resulted in substantial savings during the construction of the bridges along the route.