Back Creek is a 16.8-mile-long (27.0 km) [1] tributary of Conococheague Creek in south central Pennsylvania in the United States. [2]
The uppermost reaches of the creek, flowing through the Letterkenny Army Depot, are known as Rocky Spring Run [2] or Rocky Spring Branch.
Back Creek joins Conococheague Creek approximately 0.33 miles (0.5 km) below Williamson. [2]
39°50′55″N 77°48′02″W / 39.8486°N 77.8005°W