200 million years

I first encountered the Palisades, a set of massive cliffs overlooking Manhattan from across the Hudson River, out of desperation. At the height of the COVID-19 pandemic, I felt an all-consuming urge to get out and explore. For me, that meant jumping on my bicycle and riding deep into the city and then out of it.

One spring day, I rode across the George Washington Bridge into New Jersey. Ten minutes after rolling into the town of Fort Lee, I found myself engulfed in dense woodland abutting a soaring rock wall. Cyclists sped past me as I slammed on my brakes to gawk at a bald eagle’s nest with a million-dollar view of the Manhattan skyline.

Palisades Interstate Park emerges suddenly out of a section of industrial sprawl and covers around 2,500 acres of riverfront forest. Rising about 500 feet from the water’s edge, the park’s namesake is a line of diabase (a dark-colored igneous rock) and basalt cliffs that run along 50 miles of the Hudson River. From the western edge of Manhattan, the National Historic Landmark looks like giant wooden fences, hence the cliffs’ Indigenous Lenape name, wee-awk-en or “the rocks that look like trees.”

For many New Yorkers, the Palisades serve as an all-too-rare gateway to nature, even though there are those (like me) who spent years not knowing just how accessible they are. Yet they aren’t just an easy, albeit overlooked, escape from one of the densest cities in the United States. The cliffs are a repository of deep geological time that was nearly lost to the incessant pressures of industrialization.

History of the Palisades

Around 201 million years ago, as the Triassic gave way to the Jurassic, and the Pangaea supercontinent began to break apart, a series of dramatic volcanic eruptions took place. The activity was spread over less than a million years—a blink of an eye in geological terms. This led to a major upheaval in geology, climate, and biology covering a 4.2-million-square-mile area known as the Central Atlantic Magmatic Province, or CAMP.

(In 250 million years, this may be the only continent left on Earth.)

The Palisades are within that zone, at the eastern edge of the Newark Rift Basin that was once a body of water “more like present-day Lake Tanganyika or Lake Malawi than anything else nearby,” says Sean Kinney, a postdoctoral research scientist at Columbia University’s Lamont-Doherty Earth Observatory.

As North America began to tear itself away from North Africa, lava intruding into the sedimentary rock under the Newark Basin formed the Palisade Sill, a kind of container of magma that slowly cooled, altering the size and makeup of the rock. Kinney uses the analogy of a doughnut being injected with jelly, as he points out the clear contact point that can be seen along the base of the cliffs, where blocky lake rock gives way to the sill’s massive trunk-like basalt.

Because of the speed and scale of the volcanic activity, the Palisades are an ideal place for geologists to read rock. By drilling out cores and looking at the mineral deposits over time, they can get a clearer picture of how the Newark Basin’s water levels changed over time. The unprecedented scale and speed of volcanic activity during the CAMP event means the geological record, layer by layer, is spread over shorter time scales than what most geologists are used to having at their disposal.

Paul Olsen, a professor at the Lamont-Doherty Earth Observatory, became fascinated by the Palisades as a teenager, when he and a friend made headlines for their discovery of dinosaur footprints at a quarry near Livingston, New Jersey.

Today, his interests have expanded into how the shifting orbital patterns of our planet might have contributed to climate-influenced mass extinction events. His research is centered on this overlooked corner of the world. “We have cores here where 25 meters of rock corresponds to a 20,000-year lake cycle,” Olsen says. “So a human lifetime can actually be seen in a few centimeters of rock.”

(These dazzling rock formations stand where dinosaurs once roamed.)

PHOTOGRAPH BY RUSSELL KORD, ALAMY

Creating Palisades Interstate Park

Geologists—including Olsen and his team—often depend on controlled quarrying operations to gain access to layers of exposed rock. But runaway mining over a century ago almost obliterated the Palisades, taking the geological record and natural splendor of the area with it.

The Palisades was a source of rock for use in roads and railways, both of which were spreading across New Jersey and New York at a rapid clip at the end of the 19th century. To obtain the rock, miners would blast the cliffs with dynamite, collecting the broken-up boulders left behind when the smoke cleared.

The first mumblings of discontent about the frequent explosions across the Hudson came from people with deep pockets and coveted backyard views. But the Palisades Interstate Park Commission (PIPC), established in 1909, is really the direct result of lobbying by the New Jersey State Federation of Women’s Clubs, a civic organization. The geological value was not the main focus. Instead, activists were concerned about losing one of the few natural refuges within an afternoon’s trip from New York City and the surrounding towns.

“A lot of people look at open space as unused land,” says Carol Ash, who was the PIPC’s executive director from 1999 to 2006 and is now the chairperson of the nonprofit Palisades Parks Conservancy. “The Palisades is special, and it needs to be kept special, which has always involved a bit of a fight.”

How to visit the Palisades

One of the first things you notice on a visit to the Palisades is how little information there is on the region’s history. Signs are rare and many sections, while manicured, feel wild, making the transition from city or suburb to nature all the more abrupt. While that may not be intentional, it’s clear that exploration is the point.

(Here’s how to explore a billion-year-old volcanic mystery along Lake Superior.)

“There’s no visitor center or signs explaining what you’re seeing along the way,” says Joshua Laird, the current PIPC executive director. “I think that’s at least partially a function of the fact that the park was founded so early and we were inventing the model. There was no National Park Service to look at when we were starting these parks.”

In all, the park is home to more than 30 miles of interconnected hiking trails, which are well-marked and—with the help of a map—can lead to a customizable day along the cliffs, into the woods, and down to the shoreline. The most popular and most challenging route is Giant Stairs, a rock scramble over the very boulders that early industrialists and miners coveted so dearly.

There are also opportunities to get on the water. Outfitters like Hudson Kayaks offer rentals from the Alpine Picnic Area, which is easily accessible by car or bicycle. Cyclists flock to 9W, a road with wide shoulders and formidable climbs, and to Henry Hudson Drive, which skirts the bottom of the cliffs and is closed to car traffic on certain holidays.

(This New York State rail trail isn’t just epic, it’s also accessible.)

Today, the State Line Lookout, off the Palisades Interstate Parkway, is one of the most popular starting points. That’s partly because of the panoramic views over the cliffs and the Hudson below. An easy two-mile hike from the viewpoint leads to a stone tower and a rare tangible glimpse into the region’s past: a monument to the women who saved the park.

Much of this region’s history—its long cycles of extinction and evolution; its original inhabitants; how it was nearly lost—remain hidden to most of the 750,000 people who visit the Palisades every year. But the park is testament to the stories that lie underfoot—and just how many of them a repeat visit can reveal.