I say that there is no way it could exist in most states. Not enough land to hide a breeding population. The Pacific Northwest though, where all the Indian legends come from, and with mountains and valleys that stretch far up into Canada and have very remote/hard to get to places? Sure. I could see it happen there.
That's were these yokels on that Finding Bigfoot show should be looking, not wasting their time in other states like Ohio and such. Also, they need to stop messing around with fireworks and all that other hokey stuff. If this animal is real, it's very smart and very shy, and it's not going to walk up and see what you are doing. That might be a rare thing that happens, but my theory is we killed off all the less elusive ones thousands of years ago and all that was left was the ones genetically prone to be shy and elusive. They say that's one of the reasons why Coyotes and Mountain Lions are so elusive these days. The dumb or non-shy ones all ended up dead. On that show, they aren't even de-scenting and camouflaging themselves. Good luck with that.
I think that Finding Bigfoot show only hurts the cause. Clownish stuff giving the people serious about it a bad name IMO.
Mainly I look at it this way- it exists in the fossil record from only a relative short few thousand years ago where it was thought to have gone extinct. They think it traveled along a land bring the Indians also used to get here during low sea levels. Many of the plants in the pacific northwest that could sustain them also existed in the same Asian lands the fossils show they lived in. Too many animals were known to exist by natives in the world for eons and the white man said was myth, and they turned out to be proven wrong. Why not one more?
If it wasn't for that darn Patterson film I'd probably say "no way it exists". Every film I've seen since then is an obvious fake, even the new one that just popped up today in the news, but that Patterson film and the enhancements that show even more details just makes me wonder about the possibilities.
If anybody hasn't watched those enhancements by that guy on Youtube who is an expert on video manipulation to bring out details, you've got to do a search for him on Youtube and watch more of his stuff. Really blows my mind...
Disclaimer- I don't believe in ghosts, unicorns, little green men abducting people out of beds, that there really is such a thing as a free lunch, and so on...