Pine Creek flows through the park and has carved the gorge through five major rock formations from the Devonian and Carboniferous periods. Native Americans once used the Pine Creek Path along the creek. The path was later used by lumbermen, and then became the course of a railroad from 1883 to 1988. Since 1996, the Pine Creek Rail Trail has followed the creek through the gorge. The Pine Creek Gorge was named a National Natural Landmark in 1968 and is also protected as a Pennsylvania State Natural Area and Important Bird Area, while Pine Creek is a Pennsylvania Scenic and Wild River. The gorge is home to many species of plants and animals, some of which have been reintroduced to the area.