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
Lake Champlain Seaway covered by the Lakes to Locks Passage. Lake Champlain Seaway The Lake Champlain Seaway was a canal project proposed in the late 19th century and considered as late as the 1960s to connect New York State's Hudson River and Quebec's St. Lawrence River with a deep-water canal. The objective was to allow easy ship traffic from New York City to Montreal through Lake Champlain, lowering transportation costs between the two cities. Though supported by business groups in New York and Quebec, it proved economically unfeasible. Prohibitive costs (estimated at $100 million in 1900), opposition from railroads, and the diminishing utility