Holy creepers. The wiki is horrifying. Your movie script is set, just don't have the helicopter show up until after the unwinding of the horror is complete, maybe throw in a caretaker or local perp still active in the area.
Still missing mans belongings stuffed in a tree with a female (maybe?) skeleton found near the sign, man deemed far to weak to have built the sign. No tools found, a recording of a man screaming for help, and the felled birch tree sign made of logs thats estimated to have taken 2 days to build. Sign was estiamted to be built 2 yrs before.