Ohiopyle Falls, Fayette County

Location: Fayette County, Ohiopyle quadrangle. Ohiopyle State Park; approximately 39º 52' latitude and 79º 29' longitude.

Size: Ohiopyle State Park is over 19,000 acres in size.

One of the many waterfalls Ohiopyle.

Geology: Ohiopyle Falls shows evidence about how the falls has formed. Upstream from the falls, the Youghiogheny River flows on a thick layer of horizontal, erosion-resistant Pottsville Sandstone. Downstream from the falls the sandstone layer has been removed by erosion causing the river to flow at a lower level. The erosion of the sandstone occurs at the falls. The thick sandstone layer has two well developed sets of vertical fractures: one set parallel with the flow of the Youghiogheny River and one set at right angles to the flow. These fractures and the flat surfaces at the top and base of the thick sandstone layer are planes of weakness that allow the river to erode the sandstone layer one block at a time. The size and shape of the blocks is determined by the thickness of the sandstone layer and the spacing of the two fracture systems. Two blocks that have been eroded from the falls and moved several feet downstream occur at the left side of the photograph. As blocks are eroded from the front of the falls, the falls migrates upstream. the sandstone surface also is eroded by scour as is indicated by potholes that occur on the surface upstream from the falls and near the observation deck.

Heritage value: Site is scenic, educational, and recreational.

Heritage status: Site is secure as part of the state park.

How to Access: Visit the Ohiopyle State Park web page of DCNR.

Facilities: Various - see the Ohiopyle State Park web page of DCNR.

References: Park Guide 7

For information regarding geologic features and PNHP, contact Jim Shaulis of the Pennsylvania Geological Survey at 717–702–2037.