Not so much a Hanging Bison, more a magnetic Petling Tube!
These three Caches set between the two Low Water pinch points, were all unique, recycled, antique artifact containers. The original container here was an antique, cast iron fence finial pin, found in Lockdown Calstock, now recovered by CO for off site maintenance. Temporarily replaced with yet another Petling Tube, hidden in full view, when viewing from the correct angle. Unfortunately, it must have been the weight of the original cast iron container being too much for the tree in the spoiler image below, as it has now crashed to the ground, taking the original hide attachment with it.
Recovery will be challenging, the terrain is certainly hazardous. Wet bladder wrack seaweed, and excedingly muddy and greasy rocks need to be negotiated, not to mention tangled branches, waiting to entangle the unwary GeoCacher.
Original Spoiler
Tree still there, but crashed down, and concealing the new hide.