Beaver Run is a tributary of Buffalo Creek in Union County, Pennsylvania, in the United States.

The stream then turns north for more than a mile and flows through a shallow valley before crossing Pennsylvania Route 192 and reaching its confluence with Buffalo Creek.

[1] Beaver Run joins Buffalo Creek 8.60 miles (13.84 km) upstream of its mouth.

However, Beaver Run was not designated by the Pennsylvania Department of Environmental Protection as an impaired waterbody until 2008.

Despite this, it is not a major contributor of degradation to the main stem of Buffalo Creek, due to its low discharge.

In 2000, row crops and streambank erosion were the largest sources of sediment in the stream, comprising 1,066,189 and 197,654 pounds (483,615 and 89,654 kg) of the annual load, respectively.

[1] The stream's watershed is entirely within the Appalachian Mountain section of the ridge and valley physiographic province.

[3] The average annual rate of precipitation in the watershed of Beaver Run is 44.5 inches (113 cm).

[3] The total amount of impervious land in the watershed could potentially rise to 41 percent in the future.

[3] A total of 325 acres (132 ha) of land in the watershed of Beaver Run is on slopes of greater than 3 percent.

There are 0.9 miles (1.4 km) of unpaved roads in the watershed and they occupy an area of 2.50 acres (1.01 ha).

[4] Beaver Run was entered into the Geographic Names Information System on August 2, 1979.

[6] A concrete tee beam bridge carrying Pennsylvania Route 45 was constructed across Beaver Run in 1940.

[7] In the original assessment of Beaver Run by the Pennsylvania Department of Environmental Protection, the stream was not found to be impaired.

However, in September 2006, the Buffalo Creek Watershed Association petitioned the Pennsylvania Department of Environmental Protection to classify the stream as impaired, as chemical and biological signs indicated a lower level of water quality than the Pennsylvania Department of Environmental Protection's assessments had originally indicated.

[4] In a 2008 report, the watershed of Beaver Run was ranked second amongst sub-watersheds in the Buffalo Creek drainage basin for restoration priority.

[4] Only 0.7 miles (1.1 km) of streams in the watershed of Beaver Run have a vegetated riparian buffer.

[4] Urban land and farm animals are the largest source of pathogens, at 6.497 × 1015 and 1.389 × 1015 organisms per month, respectively.