Geology
The park lies in a glacially altered, hilly terrain referred to since the 1750s as “the Endless Mountains.” The varying layers of Devonian age sandstone and shale of the Catskill Formation are exposed in the 80-foot deep gorge of Fall Brook.
The crystal waters of Fall Brook tumble over three picturesque waterfalls, each about ten feet in height, before joining the waters of Silver Creek near the eastern border of the park. Thriving in the cool, moist conditions of the gorge are mosses, liverworts, and ferns.
About 300 feet from the mouth of the gorge on the south side of Fall Brook, and easily reached from the picnic area, is the bubbling salt spring which is the park’s namesake. The water from the spring is very high in chloride, sodium, and dissolved solids, revealing the marine origin of the sediments.
The spring bubbles, due to methane gas created by the breakdown of organic matter in the ancient sedimentary rock. The commercial extraction of both salt and oil was attempted in the late 19th and early 20th centuries, but did not prove profitable and so was discontinued.
Fall Brook Natural Area
Encompassing the gorge and the old growth hemlock forest on both the east and west rims, the Fall Brook Natural Area was established “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.”
Visitors can experience what Pennsylvania’s forests were like 300 years ago. Towering one hundred feet and more above the gorge is one of the last old growth hemlock forest tracts remaining in the commonwealth. Old growth forests exhibit complex ecosystems not found in other regional forests, and involve a delicate balance between nutrients, plants, and animals.
At one time, Pennsylvania was largely covered by this type of forest, but most have fallen prey to the pressures of commercial and industrial activities. The trees in the park now face the threat of infestation from hemlock woolly adelgid, a non-native insect infecting many of Pennsylvania’s hemlock trees.
This unique habitat and the rich diversity of natural habitats found elsewhere in the park, including mixed hardwood forests, grasslands, overgrown meadows, streams, and wetlands, attract a wide variety of birds and wildlife.
More than 150 species of birds have been recorded at the park. The combination of Susquehanna County’s cool climate and the park’s deep gorge and coniferous habitat provide ideal conditions for some species of birds that are more commonly associated with the north, like:
- Common raven
- Hermit thrush
- Magnolia warbler
- Blackburnian warbler
- Winter wren
- White-throated sparrow
A “Birds of Salt Springs State Park” checklist is available at the office. Wildlife at the park includes:
- White-tailed deer
- Black bear
- Bobcat
- Eastern coyote
- Red fox
- Porcupine
- Beaver
- Striped skunk
- Raccoon
- Red squirrel
- Flying squirrel
A wide diversity of plants can also be found, with spring providing the best time for wildflower viewing.