I doubt it, because you would think that at the very least, some skeletal remains would have been found by now.
I used to feel the same way, but then one summer near where we go camping, we found a dead elk that someone had shot out of season. Over the next few weeks during archery season, etc., we watched that mature cow elk TOTALLY disappear. First the coyotes and other scavengers got the meat, other animals and birds got the fur, ants got ay little bits of other stuff, and squirrels, rats and other rodent type animals chewed the bones to nothing. When you think about it, if nature didn't work that way, the forests would be totally covered with deer, elk, moose, bear, rabbit, squirrel and other bones, right?
Re: bigfoot - I've never seen one, but that doesn't mean they DON'T exist. . . .