Big Foot has all the characteristics of an Elemental.
Are Elementals telepathic?
Ever been way out in the swamp and suddenly have a vivid mental image of yourself at the current moment, except seen from a distance? Kinda weird
Anyway, assuming they are would explain why they can be so elusive.
Another thing, when out in the swamp or thicket, that distant (or not so distant) sound like a wooden bat or stick hitting a tree, isn't made that way. It's done by clapping massive palms together near the face while forming a resonant cavity in the mouth with lips pursed and open. Humans can do it but not with the same force or resonance.