Mann Pond was a surprise for me. I was exploring the Vernon S. Walker Wildlife Management Unit, using a map (see below) that did not go as far as Mann Pond.
Please be aware, hunting is allowed here. Wear bright orange. Or better yet, visit this land on a Sunday when hunting in Maine is not allowed.
This is a bison tube hanging behind a tree. But, I left it bright orange, so should be quick to spot. The "roads" in this area are mostly flat. But to get to this cache you will be going down a rather steep trail.