One of my favorites — maybe the best ending of any Hollywood screenplay.

I don’t know the novel or the history of the script or how John Ford worked with writers. Is the note to Winton Hoch from Nugent or Ford? I’m guessing that the novelesque action paragraphs and instances of “directing from the page” are — like the note to Hoch — intended to give suggestions to the director and crew, and since Nugent had written for Ford for some time the two had probably evolved a system that worked for both of them. I’m guessing Ford found Nugent’s elaborations helpful. Different situation for a spec writer seeking to impress a reader nowadays of course. Still as you say, the writing is very visual; in spite of the long sentences and paragraphs, the style is very succinct and action-oriented. (I just read that Nugent had begun as a journalist.)

“He runs in, looking around him. He sees the little dog, dead on the ground. And then he sees a shadowed something…”

Put line breaks after each of those sentences and you’ve got a Walter Hill-type script.