Slide-Rock Bolters

Below is the story that the movie/pictures are based on.

Way up in the mountains of Colorado lurks the slide-rock bolter. This creature has a huge head, slits where its eyes should be and a wide mouth with long, sharp teeth.

The diet of the slide-rock bolter is Colorado tourists. The slide-rock bolter will lurk at the top of a mountain peak, secured in place by its forked tail which has hooks in it, and watch for tourists. An unwary tourist, innocently sight-seeing through the Rockies, might suddenly find himself confronted by a slide-rock bolter tobogganing down the mountain towards him, its wide mouth gaping open. Before you can say George Washington, the slide-rock bolter will have scooped up that tourist and be resting on the next mountain peak, waiting for dessert to stroll by.

For a while there, some folks tried to rig a trap for the slide-rock bolters by stuffing a dummy with poison or explosives, dressing it in bright, touristy clothes and putting a guide book in its hand. But soon enough, those slide-rock bolters were seeing through the disguise and began eating the trap setters as appetizers, so they abandoned the practice.