We took this ride a few weeks ago. (Reading Blue Mountain and Northern Railroad). Reading to Jim Thorpe and return on old RDC cars. They run steam on occasion. Mr. Mueller owns the railroad and he was on our car for the trip.
Best part is in Jim Thorpe you can take another train ride up the Lehigh Gorge Scenic RR. We got a cab ride there in a GP39 - 17 miles!
Cass is great as well if you don't mind driving over the mountains. Best to stage overnight in Staunton or Harrisonburg VA. The observation car right in front of the Shay is the ticket. You can feel the boiler heat from a few feet away as it grunts it's way up the mountain.
I thought he was running that big ole steamer more frequently as of late but now that I think about it that freaking thing probably needs all kinds of maintenance. Andy also used to own a mig, I don't know if he still has it anymore though. Theirs also a narrow gauge that runs up in Ashland too near the pioneer coal mine and tunnel which is fun to do. We bricked up the front of my aunts house from some of the old rubble from the roundhouse that they tore down from the St. Clair yard back in the day. Cleaning old bricks with a screw driver lol. Lots of RR history and stuff to see around the region anymore, glad you enjoyed your trip!