Apparently, bigfoot and sasquatch tracks seem to have been identified as young black bears, who can walk in a way that their rear feet step into the same prints as their front feet, creating that "bigfoot" like shape. Also, young black bears can sometimes stand on their hind feet, looking kind of ape-like from a distance, especially with a blurry camera.
That said, in a world where primates such as gorillas exist, it wouldn't be shocking to find out that bigfoot and sasquatch and such are basically just apes. Science seems to suggest that bigfoot doesn't exist, but in a world where crazy things like the duckbilled platypus exist, a creature that's basically a skinnier ape that walks on hind legs doesn't seem really all that farfetched.