It is approximately 2.3 miles (3.7 km) long and flows through Davidson Township, Sullivan County, Pennsylvania.

The stream is acidic and is considered by the Pennsylvania Department of Environmental Protection to be impaired by atmospheric deposition.

After some distance, the stream turns east-southeast and receives the tributary Shanty Run.

[2] During average flow conditions, the discharge of Quinn Run is 1111 gallons per minute.

The concentration of aluminum in the stream is 0.114 milligrams per liter during average flow conditions and the pH is 5.75.

[3] Quinn Run is considered by the Pennsylvania Department of Environmental Protection to be impaired by atmospheric deposition due to pH.

[6] Quinn Run is designated by the Pennsylvania Department of Environmental Protection for use by aquatic life.