I found somethin similar to that on a dead end road that ends at MT lake. Was walkin through the brush bout 50 yards off the road headed toward the lake and noticed this tube made out of pvc bungee strapped to a tree trunk. Took a look to see what was inside and was a bit suprised to find some pics of some nude 40 something lady(?) along with a note that said, thanks for the pictures hope you enjoy these.

Takes all kinds.