I was never fascinated by rocks growing up, but the older I’ve gotten the more I’ve come to appreciate the incredible geologic features that I find outdoors.

No matter if it’s a giant rock wall, an outcropping overlooking a vista or a boulder field, I’ve become interested in seeking out beautiful geologic examples throughout the Commonwealth.

Luckily we live in a place dubbed “Rocksylvania,” a perfect place to find what I’m looking for.

And, as a state park lover, we have plenty of great places to visit to see these awesome natural wonders.

Here’s a few of my favorites.


Trough Creek State Park
Located in Huntingdon County, Trough Creek State Park is a great place to see beautiful geologic features in the Commonwealth.

The 541-acre park is a scenic gorge formed as Great Trough Creek cuts through Terrace Mountain before emptying into Raystown Lake. One of the coolest features is Copperas Rocks and Balanced Rock.

Copperas Rocks is cliff surface visible from the road running through the park. It is named for the coppery-yellow stain on the surface.

Balanced Rock is a huge boulder perched on the edge of a cliff overlooking Great Trough Creek far below. Balanced Rock is an “erosion remnant” that has hung there for thousands of years.

Trough Creek is a great park to send the day exploring, with scenic vistas, hiking trails an ice mine and a waterfall.


One scraggly looking tree perseveres among a pile of boulders with more trees and forest in the distance.

Photo by Tiffany Raeburn, Hickory Run State Park

Hickory Run State Park
The Boulder Field at Hickory Run State Park is something that has to be seen in person. Pictures do not do it justice.

The 15,990-acre Hickory Run State Park lies in the western foothills of the Pocono Mountains in Carbon County. The Boulder Field, a striking boulder-strewn area and a National Natural Landmark, is the park’s crown jewel.

About 20,000 years ago, a giant sheet of ice approximately one-mile thick straddled Hickory Run. The western part of the park was beneath the glacier while the eastern part east was not covered by the glacier.

The Boulder Field was created in the unglaciated area when the glacier scraped the land. As a result, a large area of 400 feet by 1,800 feet is covered in the rock debris. According to DCNR, some of the boulders are 26 feet long.

A large hole in the ground with an observation platform hanging over the top. you can see rock debris and small plant growth along the ridges of the decending hole.

Photo by Tasha Ferris, Archbald State Park

Archbald Pothole State Park
After visiting all 124 state parks, I’d have to say Archbald Pothole State Park in Lackawanna County is one of the strangest I came across.

The main feature of the park is – yup, you guessed it – a giant pothole. The geologic feature formed during the Wisconsin Glacial Period, around 15,000 years ago.

The pothole is 38 feet deep, the diameter of which decreases downward. According to PA DCNR, the largest diameter is 42 feet by 24 feet. At the bottom it is 17 feet by 14 feet.

The pothole has a volume of about 18,600 cubic feet, so could hold about 140,000 gallons. It would take 35 fire truck tankers to fill the pothole.

While you can’t climb down the pothole, it is something very unique to look at.

Christian Alexandersen 2022

Written by Christian Alexandersen

Christian Alexandersen ran one mile in each of Pennsylvania’s 124 state parks and has been sharing his passion for public lands with us since 2021. Christian is the host of the Hemlocks to Hellbenders Podcast – which highlights our state parks, forests and great outdoors. You can listen wherever podcasts are found, including Spotify, Apple Podcasts and Google Podcasts.

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Cool Geologic Features Found in PA State Parks