Washington County, New York is part of the Great Appalachian Valley (also known simply as the 'Great Valley') which is a long narrow valley strip often between tall mountain ranges. The county transitions from the Taconic Mountains to the Adirondack Mountains, and from the Lake Champlain Valley to Hudson River Valley. Much of the county is part of the slate valley of the Upper Taconic Mountains (Taghkanic, meaning 'in the trees'). The eastern boundary of Washington County is the New York–Vermont border, part of which is Lake Champlain. This is also the border with New England proper. The northern end of the county is
Champlain, New York Champlain, New York Champlain is a town in Clinton County, New York, United States. The population was 5,754 at the 2010 census. The town is located on the west shore of Lake Champlain, near the north end of the lake. The town occupies the northeast corner of Clinton County and the state of New York. Within the town are two villages: Champlain and of Rouses Point. Nearby Lake Champlain was an important military and trade route during the colonial period. The lake and the town were named in honor of Samuel de Champlain, who first surveyed the area in 1609.