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
Tupper Lake (town), New York water body in the southwest part of the town, and crosses the county line into St. Lawrence County. New York State Route 3 joins New York State Route 30 at Tupper Lake village; the highways are conjoined through the eastern part of the town. The Raquette River, a northwest flowing tributary of the St. Lawrence River, flows past Tupper Lake village. As of the census of 2000, there were 6,137 people, 2,429 households, and 1,530 families residing in the town. The population density was 52.2 people per square mile (20.1/km²). There were 3,118 housing units at an average density of