| Rough Run | |
| Source1 Location: | plateau in Davidson Township, Sullivan County, Pennsylvania |
| Mouth Location: | West Branch Fishing Creek in Sugarloaf Township, Columbia County, Pennsylvania |
| Mouth Coordinates: | 41.304°N -76.3922°W |
| Progression: | West Branch Fishing Creek → Fishing Creek → Susquehanna River → Chesapeake Bay |
| Name Etymology: | named for the speed of its waters and the dense foliage surrounding it |
| Length: | 1.3miles |
| Source1 Elevation: | between 2240feetand2260feetft (andft) |
| Mouth Elevation: | 1142feet |
| Basin Size: | 0.72sqmi |
Rough Run is a tributary of West Branch Fishing Creek in Sullivan County and Columbia County, in Pennsylvania, in the United States. It is approximately 1.3miles long and flows through Davidson Township in Sullivan County and Sugarloaf Township in Columbia County. The watershed of the stream has an area of 0.72sqmi. Glacial till and bedrock consisting of shale and sandstone can be found along the stream. It is named for the speed of its waters and the foliage along the sides of the stream.
Rough Run begins on a plateau in Davidson Township, Sullivan County, not far from the edge of the West Branch Fishing Creek watershed. The stream flows south-southwest for a short distance before turning south-southeast and dropping off the plateau. It begins to descend steeply in a valley. After a few tenths of a mile, the stream turns south-southwest again and exits Sullivan County after several tenths of a mile.
Upon exiting Sullivan County, Rough Run enters Sugarloaf Township, Columbia County. It continues flowing south-southwest and steeply descending. After several tenths of a mile, the stream turns southwest for several hundred feet. It then turns south-southeast for several hundred feet and reaches the slope. The stream reaches its confluence with West Branch Fishing Creek immediately afterwards.
Rough Run joins West Branch Fishing Creek 2.82miles upstream of its mouth, only 0.06miles downstream of the mouth of Peterman Run.
The elevation near the mouth of Rough Run is 1142feet above sea level. The elevation of the stream's source is between 2240feetand2260feetft (andft).
For most of its length, Rough Run is on a glacial till known as the Wisconsinan Bouldery Till. The surface is largely covered with boulders and it is a diamict. The Wisconsinan Boulder Till is typically at least 6feet thick. It is upper reaches, the stream flows over bedrock consisting of sandstone and shale. The sandstone and shale are interbedded and are red and gray in color. The bedrock's diamict is reddish-brown to yellowish-brown.
The watershed of Rough Run has an area of 0.72sqmi. The stream is entirely within the United States Geological Survey quadrangle of Elk Grove. Its mouth is in the northernmost part of Sugarloaf Township, Columbia County.
Rough Run was entered into the Geographic Names Information System on August 2, 1979. Its identifier in the Geographic Names Information System is 1185512.
Rough Run is named for the rapid speed which its waters flow at and also for the dense foliage that occurs along it.