Powdermill Run is a 4.36 mi (7.02 km) long 2nd order tributary to White Oak Run in Westmoreland County, Pennsylvania. This stream passes through Powdermill Nature Reserve, the field station of the Carnegie Museum of Natural History.

Variant names
According to the Geographic Names Information System, it has also been known historically as:

Powder Mill Creek
Powder Mill Run
Powdermill Creek
Tributary No.1 to White Oak Run

Course
Powdermill Run rises on the Linn Run/Clear Run divide about 1 mile west of Bald Knob in Westmoreland County. Powdermill Run then flows northwest to meet White Oak Run about 0.25 miles southwest of Weaver Mill, Pennsylvania.

Watershed
Powdermill Run drains 4.22 square miles (10.9 km2) of area, receives about 52.1 in/year of precipitation, has a topographic wetness index of 359.94, and has an average water temperature of 8.58 °C. The watershed is 99% forested.

References