The main soil in the area of Fishing Creek belongs to the Albrights series, which contains a layer of sticky, reddish-brown, gravelly silt loam. Below this is a layer of yellowish-red, gravelly, silty clay loam, which extends to approximately below ground and lies over a layer of equal portions of gravel and silty clay loam. Bedrock occurs several feet below the surface. The top of the Leck Kill-Meckesville-Calvin series in the watershed is dark brown silt loam with small pieces of sandstone and shale. A subsoil of reddish-brown silt loam from below ground is followed by a layer of sticky clay loam, below which is a bedrock of red shale.