If you're in NE Pa, look into the delaware and hudson railtrail:

http://www.nepa-rail-trails.org/dandh.html

Also, parts of the D&H run from Port Jervis to Kingston NY, following RT209 and in places are all done and signed.

There's also the Lehigh Valley railtrail, a pretty popular fall destination.. Sounds like you already know about this though, as Jim Thorpe is right by the WVRT...

How about the railtrails in NW NJ, like the Sussex Branch Trail and the Paulinskill, both are like 20+ mile Railtrails that do intersect so you could ride both and back for 50+ miles RT... or combine that with some rural road riding so you don't have to repeat anything..

Jay