Re: Need Help: Mechanicsburg PA
You'll be close to the Yellow Breeches creek and there just happens to be a nice fly shop right there in Boiling Springs as well as a terrific pub / restaurant at The Boiling Springs Hotel. For the most challenging fishing for trout in the State it's a short drive from the Springs down York Rd. to reach the Letort Spring Creek from Bonnybrook Quarry down to where it flows into the Park at Carlisle. There are others but I'm not as familiar with them and should mention that much has changed at Letort in the 35 years since I first visited this stream. Still, it's fishing and one to put on your short list.
Up the road a piece at Dauphin PA. (check your map) there is a road that leads out to Clarks Creek. Mostly a stocked stream but a good place for more challenging fishing. Those are a couple off the top of my head, enjoy.