I found the same thing when I was about 16. It was an old sack with what must had been over a 100 smut magazines in it. there was also a bag with unopened bear bottles in it.

I suspect now that there are demons who this to lead people away from God and get them trapped into a life of pornography. I mean, think about it, who carries porn and bear into the woods and just leaves it there knowing that kids could find it? If someone is an addict and they repent and want to get rid of their sinful stash, wouldn't they make sure that it was burned or at least put out with the garbage... not taken into the woods for others to find.