About 20,000 years ago, a giant sheet of ice at least one mile thick straddled Hickory Run. The western part of the park, including Hickory Run Lake, was underneath the glacier. The land to the east is higher and was not covered by the glacier, but was greatly affected by the cold climate. Boulder Field was created in this unglaciated area.
The western side of the park is covered in the end moraine of the glacier. Like a giant bulldozer, the glacier scraped the land, and rocks, sand and other debris was pushed along and frozen to the glacier. When the glacier melted and retreated, this debris was dropped, making a landscape of bogs and glacial till called a moraine.
The rocky soil of the area is called glacial till. The steep valleys of the western side of the park were carved by the billions of gallons of water that streamed away from the melting glacier. To see the change in the landscape, observe the terrain and trees as you drive Boulder Field Road. The boundary is at Hickory Run Lake on the way to Boulder Field.
The eastern side of the park did not escape the melting glacial water. Before the glacier, Hawk Run and Mud Run probably gently flowed together. But, Hawk Run drains the highlands of the unglaciated side of the park. Mud Run drains glaciated land from east of the park. The floodwaters from the melting glacier eroded Mud Run quicker than Hawk Run, creating the spectacular waterfall, Hawk Falls.
The habitats of the glaciated side of the park are characterized by:
Sphagnum moss bogs
Thin, moist soil
Blackburnian warbler, red-breasted nuthatch, and northern waterthrush are common to this habitat.
In the spring, spotted and Jefferson salamanders and wood frogs migrate to the bogs to breed.
The habitats of the unglaciated side of the park are characterized by beech and chestnut oak trees on predominantly flat land. American redstart, red-eyed vireo, and scarlet tanager are common to this habitat.
At the campground, that straddles the two areas, you can hear six species of thrush-American robin, wood thrush, hermit thrush, Swainson’s thrush, veery, and eastern bluebird.
In early May, before any trees have leaves, the serviceberry trees flower. In mid-June, the plentiful mountain laurel blooms, followed in late June to early July by the rhododendron. In mid-July, the highbush blueberries bear fruit, providing a feast for bears, birds, and many other animals.
Hickory Run has three state park natural areas, one of which is also a National Natural Landmark. A state park natural area is an area within a state park of unique scenic, geologic or ecological value that will be maintained in a natural condition by allowing physical and biological processes to operate, usually without direct human intervention. These areas are set aside to provide locations for scientific observation of natural systems, to protect examples of typical and unique plant and animal communities and to protect outstanding examples of natural interest and beauty.
This rocky landscape is a National Natural Landmark and state park natural area. Boulder Field appears striking because of its flatness and the absence of vegetation over the large area of 400 feet by 1,800 feet. Some of the boulders are 26 feet long.
Boulder Field Brochure (PDF)
Trail of Geology 2 Park Guide Hickory Run State Park Boulder Field (PDF)
This remote, emergent wetland is dominated by spruce trees and is a good example of a habitat more common in boreal areas.
This remote, nearly pristine mountain stream is lined with rhododendron and eastern hemlock. The stream has a viable native brook trout population.
The Bear Truths
Many Pennsylvania state parks are habitat for black bears. Although they appear cute and cuddly like a teddy bear, black bears are wild animals.
A black bear can scramble up a tree like a raccoon and sprint as fast as a race horse. Bears use their claws to tear apart rotting logs to find food, and those claws also work well to open garbage cans and coolers. The size and strength of a black bear is astonishing.
Black bears have poor eyesight and fair hearing, but an excellent sense of smell. Aromatic scents coming from your personal items can attract a curious and hungry bear from a great distance. Bears are attracted to the smell of toothpaste, deodorants, air fresheners, food, and even the clothes worn while cooking. Store all such items inside a vehicle. At primitive, walk-in campsites, suspend food between two trees, ten feet in the air, and three feet from either tree.
Black bears normally avoid people, but bears dependent on eating human food can become aggressive when people get between them and food.
If you come in contact with a black bear, try chasing it away by making loud noises like yelling, honking a car horn, or banging a pot. Notify a park employee if you have difficulties with bears.
Never approach a bear and be especially wary of mother bears and cubs.