The PA Wilds Trail (PAWT) is an unofficial 200 mile route through north central PA, stretching from Parker Dam State Park to the PA Grand Canyon. There are different route options due to the extensive trail network in the region. The "scenic" route has a short roadwalk and a short bushwhack, but there are routes almost entirely on trail. This is a beautiful region of the state with vast plateaus, deep canyons, views, rock formations, waterfalls, meadows, elk, many creeks, and isolation.
Here is a great video of a thruhike in 2022:
190 Miles Solo in the Pennsylvania Wilderness - PA Wilds Trail (youtube.com)
Here is a description of the route:
PA Wilds Trail | Hike Pennsylvania with Jeff Mitchell (wordpress.com)