Nature
Beyond the scenic beauty of the Palisades, the people who helped create this park at the turn of the twentieth century also preserved a unique piece of the natural world.
The Palisades Cliffs are the eastern edge of a long, low mountain ridge that rises along the western shore of the Hudson River for more than 40 miles, from just north of Staten Island to Haverstraw, New York. The 12-mile section of the cliffs contained in the Palisades Interstate Park in New Jersey is roughly in the middle of this long ridgeline.
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 Hawk Watch at State Line Lookout is a great way for citizens to engage in collecting scientific data used country-wide! Many Hawk Watchers applaud State Line for its accessibility, and during the migration season, they provide a treasure trove of information to those interested in ecology.
The Palisades Interstate Park in New Jersey has plenty of articles focusing on the natural world. Published since 1998, each article has featured a story about the human or natural history of the Palisades.
GEOLOGY
200 Million Years Ago...
As Pangaea broke apart, magma rose from deeper in the earth and forced its way into layers of sandstones and shales closer to the surface. The molten rock cooled and hardened, forming a sill of hard diabase beneath overlying layers of softer rock.
Over the millions of years since, as the softer rock eroded more quickly than the hard diabase, portions of the sill are revealed to daylight. The sill’s eastern edge is now fully exposed— the face of the Palisades.
In our Park, the contact zone can be seen at river level. This was where the molten diabase came into contact with sandstones and shales beneath it at over 1,000°F. This changed them into a metamorphic rock. These sections are often purplish in color and are crumbly compared with the hard diabase surrounding them.
11,000 Years Ago...
The glaciers of the Ice Ages also helped shape the eastern edge of the sill into the cliffs we see today, scouring away the loose rock around them.
On some of the exposed rock on the summit of the ridge, north-south running scratches, or striations, can be found, carved by debris pushed by the glaciers. Several large erratics, boulders carried from distant locations and deposited by the most recent glacier, can also be found along the summit. The Hudson River and its ancestral streams carved away remnants of the sandstones and shales that once encased the sill for millions of years.
By the time the last Ice Age ended, this continent was peopled with the First Nations. Their descendants would form the Munsee Lenape and call their territory Lenapehoking.
Today's Palisades
The type of rock that forms the Palisades is called diabase. It is an igneous rock similar to basalt. Palisades diabase consists mostly of two minerals, light feldspar and dark augite, which give the rock a distinctive “salt-and-pepper” appearance up close.
The Palisades Cliffs stick out of the ground in vertical columns of rocks, reminding people of palisades stockades. One indigenous name for this area is Wee-Awk-En, which means "Rocks that look like trees." Today, this name survives as the town of Weehawken.
The highest point along the Palisades ridge-line is at High Tor State Park in Rockland County, where the cliffs rise 832 feet (254 m) above sea level. In New Jersey, the highest point on the cliffs is Point Lookout at State Line Lookout in Alpine, 520 feet (158.5 m) above sea level.
An Unwelcome Sight...
Time and the elements continue to leave their mark on the great cliffs. The effects can be seen in the gradual processes of weathering — with pieces of cliff face that crack and flake off — or, sometimes, in an explosive burst of fury as a major rockfall sends thousands of tons of diabase into the forest below.
A huge rockfall in 1938 — still the largest in park history — led to press reports that the face of Adolf Hitler could be seen in the Palisades! In an eerie twist, just months after Hitler and his armies were defeated in 1945, a second rockfall erased the unwelcome visage from the cliffs forever...
Sending out shockwaves
A rockfall occurred at State Line Lookout at 7:28 PM on Saturday, May 12, 2012. It was recorded by seismographs at Lamont-Doherty Earth Observatory in Palisades, New York. The shock waves from the falling diabase lasted about 30 seconds.
The piles of boulders and debris left at the base of the cliffs by rockfalls are known collectively as talus. Almost all of the talus now piled beneath the Palisades has fallen from the cliff face since the retreat of the most recent glacier, around twelve thousand years ago. Over the millennia, rich soils have collected in the slope formed by the talus, and forests have taken root here beneath the ancient yet ever-changing cliff face.
Shaping the Palisades
Humans have also had a hand in shaping the Palisades. In the nineteenth century, quarries began mining the talus slope for dock-building material and paving stones.
The quarrymen called the Palisades diabase trap rock, from the Swedish Trappa, for “stairway,” because of how it tends to cleave at right angles. In the 1890s, much larger stone quarries, like Carpenter Brothers’ in Fort Lee, began using dynamite to blast the ancient diabase columns to make crushed stone for roadbeds and for producing concrete.
HUMAN INVOLVEMENT
Carpenter Brothers’ Quarry
The New Jersey State Federation of Women’s Clubs led the fight to stop the destruction of the Palisades by large-scale quarry operations. In 1900 the states of New York and New Jersey formed the Palisades Interstate Park Commission for this purpose.
In 1983 “The Palisades of the Hudson” was designated a National Natural Landmark, as “the best example of a thick diabase sill formation known in the United States. Columnar jointing, an olivine zone and thermal metamorphic effects are attributes found in rare combination at this site. The glaciated crest provides impressive evidence of the Pleistocene glacier.”
Invasive Species
An ongoing global issue is the introduction of invasive species to long-existing habitats. The invasive species often disrupt and endanger new habitats. Among the invasive species that are commonly encountered by visitors in the park are the paulownia tree, ailanthus, Japanese knotweed, Virginia creeper, and “mile-a-minute” vines.
Fauna can be invasive as well, including the Spotted Lanternfly, and the House Sparrow.
Tidewrack
As a natural park in a metropolitan setting, the Palisades Interstate Park in New Jersey offers unique opportunities to observe and learn about how we as people interact with the natural world.
Unfortunately, we often see the less savory side of humanity in the form of litter which washes up in the park or is left behind on our trails. Staff and Volunteer Groups spend hundreds of hours cleaning the park and we are so thankful for their service!
PIPC Staff Member Anthony Taranto collected litter along our beaches and recorded the "Tidewrack" for others to see.
Blue Sky Flooding & Storms
Many visitors have noticed two things: Storm damage is getting worse, and we now flood even on good days. Though tides have always shaped us during lunar cycles, we are seeing far more water in areas previously dry all year round.
Human-Driven Climate Change is to blame for these impacts to our parking lots, trail erosion, and other structural damage. The good news? Human causes mean there are human solutions waiting to be uncovered.
A Comeback Story
Peregrine Falcons are much beloved along the Palisades, where members of the public can witness them nest, hunt, and pose for the cameras!
Although they are comfortable now, it wasn't long ago that they were at risk of extinction in the local area. Through regulations and the hard work of ecologists, these apex predators have been reintroduced to our park.
Oysters & the Hudson
Oysters used to be a staple food for Indigenous People and colonists alike. Up until the Industrial Revolution, you could see oysters peddled on the streets of New York City. Today, only .001% of the original oyster population is still in New York Bay, but you can find their shells along our shoreline as remnants of a different time.
There were many human factors why the oysters disappeared, but don't worry! There are some great groups which are trying to reintroduce this keystone species to our waterways.
ECOLOGY
Ecology
Though only half a mile wide, the dramatic topography of the Palisades Interstate Park in New Jersey provides for varied natural habitats along its 12-mile length, including riverfront, talus slope, and summit.
The Hudson River is an estuary — a branch of the Atlantic Ocean, subject to the ocean’s tidal rhythms from New York Harbor about 150 miles north to Troy, New York.
Though we have mature forests, keep in mind that the entire area which the Palisades Interstate Park now exists was at one point clear-cut or developed property.
Habitats
The river water here is brackish, as incoming seawater mixes with the fresh water flow that originates over 300 miles north in the Adirondack Mountains.
This creates a rich habitat for a diversity of marine life, with a mix of fresh and salt water species living in the same area. Common species caught by visitors fishing along the riverfront in the park include catfish, striped bass, white perch, tomcod, eels, and blue-claw crabs. Fishing birds, such as herons and kingfishers, as well as bald eagles and osprey, can be seen along the waterfront.
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Forests
After 120+ years of conservation, we have mature forests on our talus slope between the shore and cliff faces. Oak-maple is the dominant forest type, with sweet gum and tulip trees also prevalent.
As it erodes, the diabase of the cliffs and talus slopes of the Palisades forms a rich soil, and dense plant growth thrives in the sunny spaces along the riverfront. Grape vine, poison ivy, wineberry, and honeysuckle are among the plants commonly encountered by hikers on the Shore Trail.
Clifftops
The summit of the Palisades can be a harsh environment. In many places the soil is only several inches deep, and hikers on the Long Path cross large sections of exposed bedrock. Still, like the riverfront below, the open sunlight along the cliff edges allows vine communities to thrive... including poison ivy. Exposed to strong winds on the summit, trees that achieve tall heights are subject to being uprooted in storms, opening still more sunlit spaces for vines and bushes to grow.
If you look closely, you may even find some Prickly Pear Cacti living along rocky cliff edges!
Vernal Ponds
Because the soil on the summit of the Palisades is too thinly spread to hold much water after a rainfall, streams typically fill or even overflow during and immediately after storms. The flow soon subsides to a trickle, however, and in dry weather these same streams all but vanish into their beds.
In other places along the summit, the underlying diabase can trap rainwater in shallow pools, called vernal ponds, which can be their own rich micro-habitats, supporting animals such as salamanders and frogs.
Tides
As the ocean current pushes up the Hudson, the river flows north for about six hours. Then, during the ebb tide, the ocean water recedes and the tide “goes out.” The current runs south for about six hours. Along the park’s waterfront, the river level changes between three and four feet during this cycle. These regular changes in the direction of the river’s flow stir the Hudson’s naturally muddy riverbed. This makes the water cloudy and gives the river its distinctive brownish-green appearance.
Pictured above is Ross Dock Picnic Area on the same day, only six hours apart.
Mammals
Among the mammals most commonly seen by park visitors are gray squirrels, eastern chipmunks, white-tailed deer, raccoons, possums, skunks, and bats.
Over the past generation, eastern coyotes and red foxes have returned to the woods here. Occasionally, a black bear is reported in the park, but these shy animals do not stay in the park for long.
The most common mammal you will meet on the trails is another human!
Reptiles & Amphibians
Among the reptiles and amphibians seen by visitors in the park are the five-lined skink, as well as black rat snakes, garter snakes, milk snakes, ring-neck snakes, northern watersnakes, and copperhead snakes. The copperhead is the only venomous snake found in the park, though unless attacked or harassed, it poses little threat to humans or our pets.
Frogs and salamanders can be found near marshy areas, and turtles, including large snapping turtles, are sometimes seen as well. All of these animals are protected by law.
Birds
Between the river and the forest heights, a great diversity of birds can be seen throughout the park. Year-round residents, those that arrive seasonally to nest, to spring and autumn migrants all find a home here.
Among the year-round residents, red-tailed hawks and turkey and black vultures are among the most memorable, seen as they soar above the cliffs, effortlessly climbing the thermal updrafts created as the sun warms the ancient diabase columns.
Some plants that bloom on the Palisades…
Photos by Ken Habermann
Most of the flora and fauna found in the Palisades Interstate Park can also be found in most wooded areas and even backyards of nearby suburban communities. Other plants are descendants of historic gardens, and someone with a keen eye can usually point out where there was an ivy patch or a tulip bed over a century ago.
DO NOT FEED WILDLIFE IN THE PARK
However well intended, it does more harm than good!
In spring and summer, it is common to encounter what may appear to be sick, injured, or orphaned young animals in the park. Most often, these animals are healthy — and safe where they are!
DO NOT DISTURB THEM
