Weird that this should happen, but my most recent issue of AMC Outdoors had an article about the most "extreme" hikes in the Northeast.
You had asked about cool hikes in your area, one of the hikes in the article is in Pennsylvannia. It didn't seem too far from you:
Black Forest Trail
Slate Run, PA
This long-distance trail loops 42 miles around the deep valleys, rocky ridgelines, and remote terrain of north-central Pennsylvania. En route it visits myriad views, streams, and backcountry campsites. It also travels one of the most difficult stretches of trail in the entire state. As it winds clockwise between the village of Slate Run and Route 44, the trail dips into several drainages scrunched between imposing mountain ridges. Knee-crunching descents and pore-busting climbs define this extreme section; one heart-pumping ascent gains 1,100 feet in only 0.7 mile.
Distance: 14 miles one-way
Info: Black Forest Trail Guide and Map (Tiadaghton Forest Fire Fighters Assn.)
Obviously 42 miles is too much for a day hike (for me anyway... christ), but the trail has many access points so you could do any amount for a dayhike.
These pages have lots of good info and maps:
http://www.midatlantichikes.com/id194.htmlhttp://www.pahikes.com/~Mike
