Bearwallow Run is a tributary of Shingle Mill Run in Sullivan County, Pennsylvania, in the United States. It is approximately 1.3 miles (2.1 km) long and flows through Davidson Township, Sullivan County, Pennsylvania. The watershed of the stream has an area of 1.02 square miles (2.6 km2). The stream is considered to be Class B Wild Trout Waters and wild trout reproduce naturally within it. The surficial geology in the area mainly consists of bedrock and Boulder Colluvium.