Davis Run begins on the northern edge of Locust Mountain on the southern edge of East Union Township.
It flows north for several tenths of a mile before receiving an unnamed tributary and entering a valley.
It then turns west for several hundred feet.
The stream then turns north-northwest and enters the Pumping Station Reservoir after a few tenths of a mile.
In this reservoir, it receives another unnamed tributary.
The stream leaves its valley and turns north when it exits the reservoir.
Approximately two-tenths of a mile further downstream, it reaches its confluence with Catawissa Creek.

Davis Run joins Catawissa Creek 30.56 miles (49.18 km) upstream of its mouth.
Davis Run begins on the northern edge of Locust Mountain on the southern edge of East Union Township. It flows north for several tenths of a mile before receiving an unnamed tributary and entering a valley. It then turns west for several hundred feet. The stream then turns north-northwest and enters the Pumping Station Reservoir after a few tenths of a mile. In this reservoir, it receives another unnamed tributary. The stream leaves its valley and turns north when it exits the reservoir. Approximately two-tenths of a mile further downstream, it reaches its confluence with Catawissa Creek.
Davis Run joins Catawissa Creek 30.56 miles (49.18 km) upstream of its mouth.
Davis Run