Yeah, there are a few experiences like that in central PA, but the lure is mostly about big water with bigger wild fish. Limestone. The freestoners come out of the mountains and fish well, but are generally too short to have much of a "system" to explore. In other words, the wilderness trips are day trips only in central PA. In the valleys you have towns and farmland everywhere, and that's where the bigger, more famous streams lay.
In NC PA you get extensive stream systems that are remote where you can hike a few miles in and set up camp, and spend the days exploring the main stem and a bunch of tribs without seeing anyone. And you have endless options for that kind of thing up there.
I will say, though, in central PA, if you just want a nice wildernessy feel with good fishing, Penns in the Poe Paddy area is an awfully nice trip. Hike and camp all you want. It's secluded, miles on dirt roads to get in there, and there's a few cabins but otherwise not a ton of permanent structures. It's a remote little valley with mature forest, and beautiful mountains surrounding you. The campground is a state park, and would be your basecamp, and you won't be "alone". But it's primitive, and you get a fair amount of room per site. Fully wooded, pit toilets, etc. From there on Penns, it's 3-4 miles upstream to the next access, and 5-6 downstream, though you can walk through the tunnel and cut off about 2 of those miles. So you can hike in and fish. There are also hiking trails going up the mountains to nice overlooks and such, and some smaller streams around, both stocked and unstocked, that can be used as side trips. Just realize that it is world famous Penns Creek, and big water. There will be a few fishermen and other recreation minded people around. And don't go the last week of May or the first of June, as that's Green Drake time and it's a circus. Also by late July through August Penns is a little on the warm side for me to feel right about fishing for trout.
