Yeah, I agree with the consensus above on Michaux SF. It's a beautiful area with tons of streams and legal access to them. My inlaws live in Hanover and when visiting them I often try to sneak up there for a few hours. If you see a guy with a red sling pack and a Titleist hat, that’s me. Most times I have my father in law tagging along with me too.
Most of the streams I’ve fished up there I'd describe as mediocre (including Mountain and Toms), but still worth exploring probably. There's one or two I've found that I'd call pretty good, but as FI mentioned, even the better streams are not really NC PA streams in terms of fish populations. An interesting personal anecdote…I think many of the streams that harbor wild trout in the area actually have Brook/Brown mixes in them, but I’ve never caught a Brown Trout in Michaux.
Acid rain and an inherent lack of buffering capacity in the geology of the area definitely impacts the trout populations. I found a gorgeous, extremely high gradient, well flowing stream and fished over half a mile of it. I eventually stopped fishing and just waded up through the stream trying to scare a fish or two...and nothing. The stream was completely dead.
Bottom line, you will run into some duds, but most streams will probably turn up a trout or two if you you’re willing to do some hiking/climbing and put up with the rhodo and tight casting conditions.