Hopper Gristmill Site is located near 156 Ramapo Valley Road in Mahwah, Bergen County, New Jersey, United States. The gristmill was built in 1764 and was added to the National Register of Historic Places on March 3, 1983.
See also National Register of Historic Places listings in Bergen County, New Jersey
References
Hopper Gristmill Site - Historical Marker Database with photo of the marker