The Ice Age in the Hudson Valley: A Geographical History

Ice capades: Journeys into the Hudson Valley’s past — the way, way past, that is

Lake Awosting at Minnewaska State Park during Fall / Gaurav Pandit, Wikimedia Commons

Take a journey to the Hudson River region’s geologic past when glaciers carved grooves into the landscape we now call home.

When you or I stand upon the great lawn at the Vanderbilt Mansion in Hyde Park, we picture ourselves living the grand lifestyle of fin de siècle Hudson Valley aristocracy, of opulent balls and market-rigging business deals held amid the stunning landscape of river and mountains. When Johanna and Robert Titus stand on that same lawn, they picture something a bit different. In their minds’ eye, they are knee-deep in water, at the edge of a vast lake that stretches from the middle of the eastern Valley counties to the middle of the western ones, and from somewhere near Glens Falls all the way to the Atlantic Ocean (which is about 100 miles further out and 400 feet lower than it is now). The couple also envisions gigantic glaciers, which cover the continent from mid-Long Island, through Chicago and Omaha, to the Dakotas, Montana, and the Great Northwest — and are in the process of melting back to the Arctic.

The Tituses, you see, are standing at the Vanderbilt Mansion circa 15,000 years BP (the geological term meaning “before present”). Robert has a Ph.D. in geology and teaches at Hartwick College; Johanna has a master’s in molecular biology and teaches at SUNY Dutchess. You may know them as columnists for Kaatskill Life and other newspapers. They recently published a delightful book called The Hudson Valley in the Ice Age: A Geographical History and Tour (Black Dome Press). Part popular science, part travelogue, it is that rare science book that is both challenging and entertaining. Readers learn about arcane geological formations like moraines, alluvial fans, and rock drumlins. Better yet, they discover where to find the remnants of these formations via hikes and drive-bys at dozens of easily accessible spots around the Valley. Consider these locales postcards from the ice age.

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We asked the Tituses to pick a handful of their favorite locations where interested parties can launch their own geological time travel. Once you start, our beautiful Valley will never look quite the same again:

The floor of glacial Lake Albany

That’s what the previously mentioned lake is known as, and the site of the Vanderbilt estate is just one of many places where you can easily imagine the soft, flat lake bottom. “Get used to the idea that anytime you see flat landscapes, you may well be literally on the floor of the lake,” Robert says. The thruway south of Kingston, for instance, was built on such a flat stretch of land, which is the result of deposits left behind as mud on the floor of the lake. “Flat isn’t all that interesting, until you realize you are at a lake bottom,” he says.


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North Lake

The area’s many lakes and rivers are all remnants of the Hudson Valley glacier, which preceded and then was overridden by the Laurentide Ice Sheet that covered all of the northern reaches of North America. As the ice advanced, it left scratches in the rock, called striations. One of the best places to find these is along the eastern shore of North Lake in Haines Falls. “Look at the bedrock at the edge of the water, and you’ll see the footprints of glaciers,” Robert says.

The Kaaterskill Clove

When deltas, like the one the Vanderbilt Mansion sits on, are carved into gorges by rivers, they are called cloves. In the Catskills, the Kaaterskill Clove — which contains Kaaterskill Falls and the Red Chasm — is an example of this; at its bottom is Palenville, which sits on a formation known as an alluvial fan. Streams from the retreating glacier all headed into this delta in a fan-shaped formation, cutting through rock, sand, and clay to create the landscape. Johanna recommends that you stop at Red Chasm. “This is a really scenic spot — many use it to swim — and you can really see how the waters from the melting ice carved the canyon,” she says.

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What’s most important about this site, the Tituses say, is that this landscape carved by melting glaciers became the touchstone of the Hudson River School of Art. “Thomas Cole painted his first paintings there, and they figure so importantly in the cultural history of the Hudson Valley,” Robert says. “And that all comes out of the ice age.”

The Mansions

The big houses built on the eastern edge of the river, including Vanderbilt Mansion and FDR’s Springwood, are all positioned on ice age deposits at the bottom of glacial Lake Albany. Hyde Park rests on one of the lake’s biggest deltas, and the mansions sit on the crest of that delta. “The aristocracy didn’t know it, but 150 years ago [when they were building their mansions] they were following the path of the glaciers,” Robert says.

They also didn’t know that one day, their houses might slip toward the river valley. The houses are not built on bedrock; they sit on soft sediments like clay. Whenever you hear of a home damaged by a landslide, usually after a heavy rain, it’s the result of land like this sliding down the slope of the prehistoric lake bed. “The sediments are very prone to landslides,” Robert says. “We have met people who lost homes that slid downhill, and we have visited homes to evaluate their threat of slides and had to tell them they were threatened. It is a present danger anywhere in the Valley where these deposits exist.”

The Tituses say they have seen evidence of the bigger mansions installing new drainage systems to shore up the grounds on which they sit. “But there is no way to know when a landslide might happen,” Robert says. “It could be 1,000 years, or 10,000 years, or in March if we get a lot of rain.” He doubts the latter, though. “The land has been there 15,000 years, so I don’t think there is an immediate threat.”


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The Pine Bush

These days, the Pine Bush Preserve in Albany County is a foliage-covered plot of hilly, sandy soil. Just after the glaciers retreated, though, it was a small desert not unlike something you’d see in Lawrence of Arabia. “All that was missing were camels,” Robert says. The sand was blown in from what is now Schenectady County, which then was one of Lake Albany’s biggest deltas. As the lake retreated, the sandy deposits at its bottom were blown by the west winds and dropped here, forming the dunes and swales that have since been overgrown. “Stand on top of the dunes and imagine what the area looked like 12,000 years ago,” he suggests.There are many more spots where you can pick up the ice age trail. Along their upper edges, the Shawangunks reveal erratic striations left by the passage of ice. Frederic Church’s Olana near Hudson sits atop a rock drumlin, a hill shaped like an inverted spoon bowl, which is a signature of glacial advance. “Each location has its own chapter. We suggest you pick up the book and go see what we saw,” Robert says, “because it is an autobiography of our great adventures.” Adventures that can take you to the dawn of your own homeland.

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