The story I was told was very distinct from the Bigfoot origin story. It involved an old rancher and three young men who worked as hands on the ranch. The rancher held a grudge against the Mogollon Monster, as he believed it had killed one of his sons. So his ranch hands were always armed with shotguns, and always worked as a team.
The rancher’s son had been out hunting in winter and was late returning, so the rancher rode out in the direction he said he was traveling, only to find his son’s head up in a pine tree. The body was never found.
Years passed, and the hands found the rancher’s remains in much the same way. They liked the old man so swore to hunt the beast down. One knew of a small cave in the area, so being the smallest of the three, he went inside while the other two kept watch outside.
The two were attacked, and so violently that the third knew he would have no chance if he went out to help them. Instead, noticing a crevasse in the cave just large enough for him, he squeezed in sideways as much as he could.
The beast entered the cave looking for him, and terrified beyond belief, as it reached in there and tried to claw him, deeply scratching his arm, he wedged himself firmly in the back of the crevasse. He passed out and woke up several times after the beast had gone.
The last time he woke up in the hospital. His rescuers had noticed the area in front of the cave painted with blood, and had a very hard time extracting him from the crevasse.
After he told his story, they tried and failed to find human remains, and he was in such a state of shock that he was sent south to the Arizona State Insane Asylum.
Good campfire story! Really