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 Canal Waterford, New York. Distance is based on position markers from an interactive canal map provided online by the New York State Canal Corporation and may not exactly match specifications on signs posted along the canal. Mean surface elevations are comprised from a combination of older canal profiles and history books as well as specifications on signs posted along the canal. The margin of error should normally be within 6 inches (15.2 cm). "All surface elevations are approximate." Lake Champlain has a mean surface elevation ranging between 95 feet (29 m) and 100 feet (30.5 m). Champlain Canal The Champlain Canal