Several groups augment the recreation area's maintenance and interpretive programs by presenting historic sites to the public.
Millbrook Village Society has spearheaded the raising of two barns and a 19th century gristmill, filling voids left in the village from arson and a failed dam project. The society supplies demonstrators and craftsmen to interpret lifeways to thousands of visitors during Millbrook Days each year. Volunteers operate a wagon shop, blacksmith shop, and woodworking shop open to the public.
Walpack Historical Society formed in 1986 to preserve the heritage of the Walpack Center Historic District on the New Jersey side of the park. The Society supplies docents to interpret the nearby Van Campen Inn, and holds an annual Van Campen Day.