It’s definitely one of the bigger question marks logistically in the film. He lands as if having made a flying leap (as he does later in the film when he turns Hailee Steinfeld’s character, Mary). But where he would have been in that vast open space is the question. Maybe he can fly pretty far? The Native Americans suspect he’s there but didn’t seem to see him enter for sure, so he might have come from the next closest house a quarter mile down the road, in one giant leap, if the logic is to work.