I have Ride With GPS maps from a tour I did from OH to Philly back in 2014. Going west, you'd take the SRT to Mont Clare/Phoenixville and then head into Lancaster County. Next day would be Red Run Campground in LanCo to near Heggins, PA (camping up a decent climb east of town). Then to Bloomsburg (camping in Rupert, just outside of Bloomsburg) via Ashland and the infamous Centralia. West from there to Danville. Lots of climbing in places, especially in Schuykill County.
I also have mapped out a route that I have yet to ride that links Danville to the Pine Creek Trail in Jersey Shore, PA that is part of a cross-PA ride I have been toying with. You could jump off Pine Creek in Waterville and take PA 44 up to the park. Probably a hell of a climb and likely few or no services between the Jersey Shore area and the park.