Spring Run begins in a shallow valley in Delaware Township.
It flows northwest for a few tenths of a mile before turning west-northwest for several tenths of a mile.
The stream then heads in a west-southwesterly direction for several tenths of a mile, entering Watsontown.
In Watsontown, it continues flowing west-southwest for several tenths of a mile, crossing a railroad.
The stream then turns west for  a few tenths of a mile, reentering Delaware Township and crossing Pennsylvania Route 405.
In then turns south-southwest for a short distance, reentering Watsontown and reaching its confluence with the West Branch Susquehanna River.

Spring Run joins the West Branch Susquehanna River 16.54 miles (26.62 km) upstream of its mouth.
Spring Run begins in a shallow valley in Delaware Township. It flows northwest for a few tenths of a mile before turning west-northwest for several tenths of a mile. The stream then heads in a west-southwesterly direction for several tenths of a mile, entering Watsontown. In Watsontown, it continues flowing west-southwest for several tenths of a mile, crossing a railroad. The stream then turns west for  a few tenths of a mile, reentering Delaware Township and crossing Pennsylvania Route 405. In then turns south-southwest for a short distance, reentering Watsontown and reaching its confluence with the West Branch Susquehanna River.
Spring Run joins the West Branch Susquehanna River 16.54 miles (26.62 km) upstream of its mouth.
Spring Run (West Branch Susquehanna River tributary)