This is one of two casts from the Blue Mountains outside Walla Walla, WA that shows the creature stepped on a rock while walking. This interesting detail is commented on in Dr. Grover Krantz’s excellent book.
The rock impression sticks into the foot’s fat pad almost two inches. The rock was not only driven directly downwards, but also in a forward direction, which is what would be expected from a walking creature. Also of note is the extreme splaying of the toes, reinforcing the hypothesis of the flexibility of the sasquatch foot. There are several other excellent examples of this sort of flexibility from the Blue Mountains, possibly showing the same individual.