Champlain Valley southward into the Valley of Vermont. The Vermont Lowlands are primarily underlain by sedimentary rocks, especially limestone and shale, though metamorphic rocks such as marble and slate are also present. Lake Champlain is situated in the Champlain Valley between the Green Mountains of Vermont and the Adirondack Mountains of New York, drained northward by the Richelieu River into the St. Lawrence River at Sorel-Tracy, Quebec (northeast of Montreal). Major tributaries of Lake Champlain include Otter Creek and the Winooski, Missisquoi, and Lamoille rivers in Vermont, and the Ausable, Chazy, Boquet, and Saranac rivers in New York. Lake Champlain also receives
Champlain, New York connecting New York City to the south with Montreal to the north, via Quebec Autoroute 15. Champlain is approximately south of Montreal. According to the 2010 2010 United States census, the town has a total area of , of which is land and , or 12.90%, is water. Lake Champlain and the Richelieu River are on the east edge of the town, which shares a border with Grand Isle County, Vermont. The town line to the north is the international border with Saint-Bernard-de-Lacolle, Quebec, Canada. The Adirondack Northway (Interstate 87) is a major north-south highway that begins at the Canada–United