| Spencer Run | |
| Name Other: | Spencer's Run |
| Source1 Location: | valley just south of Waller in Jackson Township, Columbia County, Pennsylvania |
| Mouth Location: | West Creek in Benton Township, Columbia County, Pennsylvania |
| Mouth Coordinates: | 41.2052°N -76.3889°W |
| Progression: | West Creek → Fishing Creek → Susquehanna River → Chesapeake Bay |
| Length: | 2.1miles |
| Source1 Elevation: | between 1180feetand1200feetft (andft) |
| Mouth Elevation: | 778feet |
| Basin Size: | 2.07sqmi |
| Tributaries Right: | one unnamed tributary |
Spencer Run (also known as Spencer's Run) is a tributary of West Creek in Columbia County, Pennsylvania, in the United States. It is approximately 2.1miles long and flows through Jackson Township and Benton Township. The watershed of the stream has an area of 2.07sqmi. Wild trout naturally reproduce in the stream. The surficial geology in the area mainly features Illinoian Till, Illinoian Leg, alluvium, colluvium, and bedrock.
Spencer Run begins in a valley just south of Waller, in Jackson Township. It flows east and enters Benton Township after several hundred feet. The stream then turns southeast for several tenths of a mile, as its valley becomes deeper. It then turns south-southeast for several tenths of a mile before turning south, crossing Waller Drive, and receiving an unnamed tributary from the right. It then turns southeast for a few tenths of a mile before reaching its confluence with West Creek not far from the northwestern corner of Benton.
Spencer Run joins West Creek 1.48miles upstream of its mouth.
The elevation near the mouth of Spencer Run is 778feet above sea level. The elevation of the stream's source is between 1180feetand1200feetft (andft) above sea level.
The surficial geology in the vicinity of Spencer Run mainly consists of colluvium and a till known as Illinoian Till, which contains silt and clay. However, at the headwaters of the stream, there is some Illinoian Lag. The sides of the stream's valley have surficial geology featuring bedrock consisting of sandstone and shale.
The watershed of Spencer Run has an area of 2.07sqmi. The stream is entirely within the United States Geological Survey quadrangle of Benton.
Spencer Run was entered into the Geographic Names Information System on August 2, 1979. Its identifier in the Geographic Names Information System is 1188165.
Spencer Run was historically a direct tributary of Fishing Creek, instead of being a tributary of West Creek.
Wild trout naturally reproduce in Spencer Run from its headwaters downstream to its mouth.
In 2004, the Columbia County Natural Areas Inventory recommended protecting Spencer Run.