Sinclair Falls is a waterfall on South Branch Grass River in St. Lawrence County, New York, in the Northeastern Highlands region, with a total height of about 25 feet. It lies about 18.8 miles south of Canton and roughly 86 miles north of Utica as the crow flies.
At 25 feet it is on the modest side for New York, where the typical waterfall with a recorded height stands around 50.5 feet; it ranks 137th of 184.
The Northeastern Highlands are the mountains of northern New England and the Adirondacks, with spruce-fir on the summits and northern hardwood forest of maple, beech and birch below, and countless lakes and boulder-strewn brooks. Fast mountain streams drop over granite and gneiss ledges in chains of falls and pools. South Branch Grass River carries 8 recorded waterfalls; the biggest of them reaches 60 feet.
There are 58 recorded waterfalls in St. Lawrence County. Basford Falls, 15 feet high, is under a mile away. Twin Falls, 55 feet high, is about 1 miles away. Bulkhead Falls, is about 1.5 miles away.
Sinclair Falls is located at 44.3381° N, 75.0458° W. The listing is based on the World Waterfall Database, one of the sources compiled by the U.S. Geological Survey in its inventory of waterfalls and rapids of the conterminous United States. The creek name is confirmed against the federal Geographic Names Information System. The position was verified on aerial imagery. Details on trails, parking and access have not been documented for this waterfall yet.