I sure don’t know where the Fenn treasure is hidden…
But we do know that it is supposed to be in the place where he planned to leave his corpse.
It’s hard to believe anyone would leave their corpse out in the open where floods, storms, and other natural occurrences would destroy your body.
It seems – SEEMS – more likely that a person would choose to die & leave their body in place like a cave. Yes, all of the animals would still be able to get to your body if you didn’t block the entrance. Maybe if you really did all this planning you would block the entrance. I don’t know why you wouldn’t.
The main point is that I would personally be shocked if the treasure is just out in the open or under a tree branch or something
Think where people would choose to be buried