Steep valley walls with rock outcrops surround both sides of the stream. Trees and underbrush stabilize the slopes and reduce the erosion. Debris from trees washed down the stream is deposited on the rocks and trapped by standing vegetation. Figure 3 Further upstream, the slope of Horsepen Run steepens considerably. There is little, if any, floodplain along this portion of the stream.
Large boulders line the bed, bank and valley walls.
Joint sets are visible and indicate that the stream bed runs parallel to two of these planes. Sand and gravel deposits are found between the boulders. The floodplain appears to have been recently disturbed from overbank flow. The bed of the stream is bedrock, with outcrops of gneiss visible. Sand and gravel deposits are present along the banks.