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 Valley water from Lake George via the La Chute River Champlain Valley The Champlain Valley is a region of the United States around Lake Champlain in Vermont and New York extending north slightly into Quebec, Canada. It is part of the St. Lawrence River drainage basin, drained northward by the Richelieu River into the St. Lawrence at Sorel-Tracy, Quebec (northeast of Montreal). The Richelieu valley is not generally referred to as part of the Champlain Valley. The Champlain Lake Valley is the most heavily populated region in Vermont, broadly stretching eastward from the lake's shore to the base of the Green