Greenbrook Sanctuary is a 165-acre woodland preserve on top of the Palisades in Tenafly and Alpine, New Jersey. The Sanctuary is managed and maintained for the use of its members by the Palisades Nature Association, a non-profit organization founded in 1946. The entrance is off U.S. Route 9W, 4.7 miles north of the George Washington Bridge (directions).
PNA Membership is open to all, membership is required for access to Greenbrook Sanctuary. Click here for new or renewal membership information.
Palisades Nature Association is a non-profit organization of conservation-minded people, founded in 1946 to preserve the natural character of the Palisades cliffs and to develop a wild sanctuary in the Greenbrook area. Today it administers Greenbrook Sanctuary to provide a place within the metropolitan area where interested persons can study nature and relax in a peaceful, undisturbed setting. To foster an appreciation of the unique Palisades environment and history, and to spread its conservation message to all ages, the Association sponsors weekly nature, geology, and ecology field trips in Greenbrook Sanctuary, illustrated lectures, and special group programs (by appointment) — all conducted by a professional naturalist. In addition, careful censuses of the flora and fauna are made from year to year to serve as scientific records of the sanctuary’s changing diversity and species composition.
Greenbrook Sanctuary is primarily an oak forest, especially along the cliff edge where red oaks, hickory, and black birch dominate. In cooler, moister, more fertile coves, sugar maple, beech, dogwood, and tulip trees are common. Swampy, poorly drained areas are covered with red maple, sweet gum, elm, tupelo, hornbeam, pin oak, ash, and willow. Common shrubs are maple-leaf viburnum, witch hazel, laurel, blueberry, wild azalea, poison ivy, grape, and, in wet areas, spicebush.
Starting in early spring, before the trees produce their leaves, the sanctuary experiences a parade of colorful wildflowers springing up from the forest floor, and the fiddleheads of twenty species of native ferns uncoiling from the dead leaves. This is paralleled in late summer and fall by an amazing variety of mushrooms, shelf fungi, and slime molds.
A five-acre pond with small adjoining bog increases the great diversity of this sanctuary. The 250-foot Greenbrook Falls is one of three major streams which drain the area and tumble down the ancient diabase cliffs into the Hudson River. Views of these waterfalls, the Palisades and Highlands to the north, and the densely populated cities across the Hudson, are possible from several promontories which look down 350 feet into the river.
Over 250 species of birds have been identified in the sanctuary. During the migratory seasons it is not unusual to observe eighty species in one day, including twenty varieties of colorful warblers and, in the fall, thousands of hawks (and an occasional eagle) soaring along the cliffs. Among the more exciting nesting birds are great horned owl, broad-winged hawk, pileated woodpecker, ruffed grouse, wood duck, scarlet tanager, rose-breasted grosbeak, worm-eating warbler, and indigo bunting.
Common mammals include the nocturnal raccoon, red fox, striped skunk, gray squirrels, chipmunk, muskrat, cotton-tail rabbit, and the secretive white-footed mouse, short-tailed shrew, and common mole. Deer, opossums, weasels, flying squirrels, and red bats are also occasionally seen.
Each March, the pond, bog, and swamps fill with the egg masses of wood frogs and spotted salamanders. Afterwards, the voices of the spring peeper, pickerel frog, and bull frog fill the spring evenings with mating songs. The dominant reptiles are eastern garter and northern water snakes, and painted and snapping turtles. Rarely, copperhead snakes, five-lined skinks, milk and black snakes, and musk turtles are seen.