PA Hickory Run State Park: Boulder Field Trail

The Boulder Field Trail is a 7-mile out-and-back hike that starts just off Rt. 534, the main road that winds through Hickory Run State Park in White Haven, PA.  I took my hiking buddy Amos the Black-and-Tan Coonhound along. This is #9 of our 2022 52-Hike Challenge. It was by far the coldest and windiest hike of the year. 

An Ice Age experience

Honey Locust, staying safe from Giant Sloths

In this Northeastern region of Pennsylvania the most recent ice sheet receded about 22,000 years ago and while the climate stayed tundra-like for thousands of years and the present day forest is somewhat recent, the trail makes for a great opportunity to read the landscape for Ice Age history.  It started almost right away with finding a Honey Locust with its inches-long purple spikes, standing alone in an old farm field. This tree developed super huge spikes to deter the Ground Sloth, a voracious herbivore. The sloth no longer survives but the Honey Locust persists in repelling browsers like deer. 

Snow squalls and high winds roared through for the whole hike

High Arctic winds roared overhead and fast-moving snow squalls added an icy look to the forest. Our hike was made all the more Ice Age-y as we hurried to stay warm - the temperature dropped twenty degrees over three hours. Amos is not too keen on high winds and the sounds through dense Hemlock forest freaked him out a little - all the more reason to keep moving. Except when he scented his first Porcupine. While he sniffed and gobbled sweet treats of porky-poo, I examined the ground cover.

Porcupine chew and poop (which Amos ate)

Porcupine "leavings" after a Hemlock bud and twig feast

The trail was sopping wet in many places (ok, flooded) so we did a few bushwacks through the woods to work around the boggiest bits. The Pocono Plateau is full of water that fills bogs, swamps, and vernal pools. Its a landscape of waterfalls and fast water creeks and rivers. The park is at the boundary of the extent of that last ice sheet. It tells a part of the ice age story that combines all that water freezing and thawing over thousands of years to create this relatively flat landscape of shattered rock. 

Close-up of red sandstone conglomerate boulder

Sandstone boulders dot the forest

This trail marks the nearby boundary of glaciated and unglaciated surfaces. The landscape that rolled, rocky and mossy green, from my ground-level view of the forest floor was the north-western extreme of unglaciated land. Taking trails further west in the park, like Shades of Death and Fireline, you will cross glaciated surfaces.  Sitting here admiring mosses and clubmoss, I imagined that 22,000 years ago I would be at the base of a mile-high sheet of ice that had ground to a halt a mile before me. Nothing would have blocked my view. The forests were yet thousands of years in the future and the iconic Ice Age savannah and its voracious Ground Sloth and Wooly Mammoths had not yet appeared. Imagine the scene of an ice sheet boundary in Greenland. Whoa.

Sphagnum Moss 

Flat-Topped Tree Clubmoss

Interrupted Clubmoss

Farther west in the park red sandstone boulders were dropped by the retreating glacier, most likely plucked from nearby ridges. Where we hiked on the Boulder Field Trail, ice-shattered rocks peeked out of the forest leaf litter, sharp and trip-worthy. Their appearance and shapes were affected but not touched by the ice sheet. I stopped to examine two kinds of Clubmoss that brightened the brown-gray day with bright green. These plants are from a most ancient lineage of vascular plants that evolved over 400-million years ago. They've seen ice sheets come and go during all those years on Earth. 

The stump is gone, giving this young tree "legs"

The soil is shallow and nutrient poor, so the best place for a tree seedling to germinate is atop a nutrient-rich Hemlock stump. Given time, the stump completely rots away while the young sapling's roots, that once reached deep into the stump, are exposed to look like legs. As the tree continues to grow maturing roots grow together and outward into the rocky substrate, anchored tightly to the ground. 

No longer "walking" but well anchored to the rocky soils.

Amos pulled me along the trail until we came to the 16-acre boulder field and the winds were wild. He did not care for that or the tricky footing of trying to walk out on the boulder field. With water beneath (I could hear the sounds of a below-surface stream) and thousands of years of moving and grinding ice-shattered rocks against each other pushed along by water and gravity, the boulder field rocks were polished and rounded. They teetered and tottered, clicked and clacked. 

Hickory Run Boulder Field

Amos kept looking up at me as if to say "What hellscape have to brought me too?!" and he refused to venture out, even though the sounds of laughing families across the field made him curious. Another blast of Arctic wind and Amos had had enough. Back to the safety of the forest!

Feeling accomplished having met his fears of wind and wobbly rocks.

This trail traveled unglaciated land. Everything to the west and north of 476 was under ice! 

He pulled me at a quick pace the three and a half miles back the way we came. Snow was flying and winds whipped the tops of the trees. Even with brief periods of sun, the snow flew and the temperature dropped. Amos was dead set on getting back to the truck - a real trick moving at fast speeds trying to place my feet carefully on the rockiest sections and working around the flooded parts. But we did it and he was pretty proud of himself and was soon asleep on the warm, swaying truck ride back to my cousin's house for a night of cozy rest.

Here's my hike video on my YouTube Channel Roamin' Bones.  Amos is zonked out at the end. Happy snoozy trails, buddy.

Notes:

Hickory Run Boulder Field -  Trail of Geology #16-059, PA DCNR

Hickory Run State Park website.