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
Ogdensburg, New York the City of Ogdensburg in 1868. It is located between Brockville, Ontario to the west and Massena, New York to the east. Beginning in the mid-19th century, Ogdensburg expanded on its role as a port city on the St. Lawrence River, becoming an important trading city and station as railroads were developed in northern New York and southeastern Canada. The Ogdensburg & Lake Champlain Railroad (later Rutland Railroad) (1849), Rome, Watertown & Ogdensburg Railroad (1853) and Portland & Ogdensburg Railway (never completed), all constructed lines through the area connecting the historic towns. In 1940 the town was the site of