I’m sorry that happened to you. I’ve ridden in Mine Falls a couple times with the Tuesday night NEMBA group ride and we’ve never had any issues. Granted, those were fairly large groups, but I’ve also walked around Mine Falls solo many times and never had any issues, close calls or concerns. I’ve seen an old beat up tent or two in the woods there, which doesn’t surprise me since it’s close to the highway and the city of Nashua, but I’ve never seen them occupied.
Hopefully, while certainly not pleasant for you, the things you experienced were very isolated issues. I know a few people who bring their kids there, including one who rode there yesterday with little ones, so I’ll mention it to her. Again, I’m really sorry you had such a bad experience there. 🙁