Big Dog Falls is a 25-foot waterfall on Smith Pond Brook in Grafton County, New Hampshire, in the Northeastern Highlands region. It lies about 3.3 miles south of Enfield and roughly 53.6 miles northwest of Manchester as the crow flies.
At 25 feet it is on the modest side for New Hampshire, where the typical waterfall with a recorded height stands around 30 feet; it ranks 67th of 115. By form it is a horsetail, where the water keeps some contact with the bedrock as it falls.
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.
Grafton County holds 98 recorded waterfalls, and several are close by. Mascoma Falls, a cascade waterfall, is about 6.8 miles away. Mink Brook Falls, is about 8 miles away. North Hartland Falls, a 40-foot dam waterfall, is about 10.8 miles away across the state line in Vermont.
Big Dog Falls is located at 43.5934° N, 72.1347° 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 exact position has not yet been verified on aerial imagery, so treat the map pin as approximate. Details on trails, parking and access have not been documented for this waterfall yet.