 Lake Champlain is in the Lake 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 and downstream of Montreal, Quebec.It also receives the waters from the Lake George, so its basin collects waters from the northwestern slopes of the Green Mountains and the northernmost eastern peaks of the Adirondack Mountains.Lake Champlain drains nearly half of Vermont, and approximately 250,000 people get their drinking water from the lake.