There could be what is called a big foot, think type of ape creature, better at hiding. As for the bone thing, bear bones are not found either. One of my sister had a good thing on this part, which I had not studied, she said, well it sure could that reason there are not bones found of bear and could be the big foot, is the porcupine, sounds funny right, not really, the porcupine eats bones for the quills. learn something new all the time.