Conversely you could block the road in various nonviolent ways ( like women and children standing in the road arms crossed ) when a particularly out of control bunch is inside the rec. area and then refuse to let them go home again until they pay the local toll; one full bag of trash per person. Frontier justice like the old "miners court". 

I did this on a small scale where I live which was on a trail leading to a known party place which was being starting to be trashed. I waited until they went in and then put up a phony little barricade with a sign saying "Please clean up after yourself before you leave". Left a few garbage bags too. And you know what, they did clean up and they even hauled off stuff that they had not littered. And they never came back. Go figure.