The Cooper Gristmill is a working, partially restored water-powered flourmill built in 1826 by Retired General Nathan Cooper, a leading citizen of Chester, New Jersey. Cooper bought the property in 1825 from Isaiah Younglove. Cooper replaced Younglove’s aging mill with the newest technology, including four sets of millstones, numerous elevators and conveyors for moving grain and flour, various machines for cleaning and sifting, and bins for storage. The mill could grind up to 10 tons of grain a day. Two overshot waterwheels generated power, using water from the nearby Black River. The mill was state-of-the-art for 1826, and a centerpiece of the rural, thriving village of Milltown.
Numerous improvements were made to the Mill during the mid-19th century, the most significant being the replacement of the original vertical water wheels with new efficient horizontal turbines. None of these improvements could keep Cooper’s mill competitive with America’s rapidly expanding milling industry consolidating in the Midwest. By 1913, the local paper reported that Cooper’s Gristmill, “the last operating gristmill in Chester Township, was about to be discontinued.”
From its closing in 1913 until its purchase 50 years later by the Morris County Park Commission, the Gristmill served a variety of functions including a place for square dances and storage. By 1963, much of its roof and interior structure were severely deteriorated, but the solid stone walls stood soundly in tribute to their original builders. In 1978, the Cooper Gristmill was again running and open to the public. Today, wheat, corn, rye, and other seeds are ground to exacting specifications.