This abandoned railway was part of the Pennsylvania/Penn Central line from Harrisburg to Hagerstown, MD. Between Harrisburg and Shippensburg, it paralleled Reading Railroad's line, which was several miles to the south. Both companies became part of Conrail in April 1976, and this line was probably abandoned around that time.
The line passed through wooded and agricultural areas. The western section is being developed as a rail trail, while the eastern section is used as a utility corridor. The utility corridor section can be easily located by the power lines, but the property owners have posted "No Trespassing" signs in several locations.
A short segment, from Isle to Carlisle, appears to still be active with a shipper that uses tank cars.