In 1954 the Park Commission received a gift of 118.9 acres from the Davella Mills Foundation. Additional acreage was acquired through a land-swap for property in Branch Brook Park which went to Newark's Barringer High School. Acreage purchased in 1962 and 1967 completed the reservation.
The stipulation for the original gift was that the land be preserved in its natural state. Therefore, the only development undertaken on this land was a small parking area and a system of walking trails that gives the public access to the interiorâ€”a minimal design by the Olmsteds in their last association with Essex County. The outcrop at Quarry Point provides a scenic lookout. The area has attracted bird watchers who observe migratory birds, such as warblers in the spring and hawks in the fall. There are no buildings in Mills Reservation.