In 1882, the waterwheels at Long Pond Ironworks, the last of many there, were built to harness the power of the Wanaque River, the only natural drainage from Long Pond (Greenwood Lake). Water was carried from the waterfall upriver to the tops of the waterwheels by canals and aqueducts. The turning wheels, which could generate 200 horsepower, operated huge piston engines that blasted air into the furnace fire, raising the temperature high enough to smelt iron from ore.