The mill, originally built by Nathan Cooper then given to his nephew Nathan A. Cooper, originally had two waterwheels. Each wheel turned 2 sets of stones for a total production of 800 lbs. of flour per hour. The penstock draws water from the dam located on the other side of NJ 24. The water is piped through a penstock then channeled in a wooden trough to the current 16', 2,000lb. overshot wheel. The wheel turns most efficiently at 8RPM, which means that only about half of the wheel's 48 buckets need to be full to turn at that speed.

The initial milling enterprise on this site on the Black/Lamington River was begun in the 1760's by Isaiah Younglove, lasting to 1788. Numerous operators and owners utilized that first mill until 1825, when Nathan Cooper bought the property including the dam, mill, mill house and water rights. The new, current mill was built in 1826 and has operated successfully into the mid-20th century.

The community was known as Milltown and Milldale at various times throughout its history.

The Milldale Mill at Chester NJ.This was later renamed the Cooper Mill.