Swallow Falls is home to the Youghiogheny River, which flows along the park's borders, passing through shaded rocky gorges and creating rippling rapids. Nearby Muddy Creek Falls is a crashing 53-foot waterfall within the park. The Youghiogheny River and Muddy Creek are white water rivers that contain severe natural hazards, such as waterfalls, violent rapids, swift currents, deep pools, underwater hydraulics, cold water, slippery rocks and rough terrain.

The Maryland Department of Natural Resources urges all visitors at these sites to exercise extreme caution in the water.

In this area you will find Conemaugh rock formation, which contains claystones, siltstones, shales, sandstones and several coal beds and fossils. These rocks date to the Pennsylvanian Period and are about 300 million years old.