I've discussed this a lot lately. Why are Southeastern people so bad about litter? I drive through the National Forests here and see, and not limited to:
couches
mattresses
old appliances
beer cans
styrofoam fast food boxes
plastic bags
tampons
oil filters
batteries
While walking through the woods or fishing a lake it's beer/soda cans, bags, dip cans, trail tape, bottles, fishing line, discarded lures, ripped clothing, literally anything they didn't want to take out.
When we went out to Colorado last Summer we hiked on some busy trails and I fished some lakes with plenty of people around, not one speck of trash. Not even a piece of fishing line or a single cigarette butt.
I've made the comment that it was so clean that if it weren't for seeing other humans, I'd think I was the first person to discover those woods or lakes. With how disgusting Southeastern people, of course not all of us, seem to be I can't blame private land owners one bit for not wanting to allow access. I probably wouldn't allow it either.