It the same way around here. Week end and events near us beer cans and fast food bags etc.
I can characterize the miscreants accurately but it is not PC to do so.
They just plain don't raise their kids and they don't care.
I thought about chasing down a couple and super gluing their cans,to their windshields, so they wouldn't lose them again. But wife and Sheriff wouldn't think highly of the idea.
We have asked for other sites when we pull in and find a mess on the site or around it. Cigarette butts stink when wet. We have seen where it looked like there must haave been a hundred people on a site.