I'm seeing this in NE PA.
I'm not from here (very rural upstate NY) and I lived in York PA area for 7 years.
Never saw this amount of trash on public land, particularly the informal shooting holes.
Up here it is a whole new world. Besides the backwards politics, welfare culture and general brook trout mentality of a so many of the locals I am absolutely appalled at the disgusting state of the public lands. It's amazing how low people can be.
Couple of the best spots I found after moving here in 2000 are now closed and as with you it's because of the trash.