With the notable exception of Stagecoach, I'm not a big fan of the movies John Ford made with screenwriter Dudley Nichols, even though these include some of Ford's most celebrated and entertaining films.
Nichols was an extremely skillful writer, with a sound sense of story structure and a good ear (usually) for colorful dialogue. But he also had a self-conscious, "literary" style -- he tended to see situations and characters in emblematic, metaphorical terms. This aspect of Nichols' work encouraged Ford to indulge his gorgeous visual expressionism at the expense of what he did best -- create cinematic spaces and places of mesmerizing specificity. The images of The Lost Patrol and The Informer are supremely beautiful but they grow claustrophobic after a while. The desert and the fog-bound city are too obviously surrogates for existential states, symbolic and airless.
In his best work Ford found ways of imbuing interiors and landscapes with an uninsistent symbolic quality -- we read them as real spaces and feel their emotional resonances on a subliminal level. We have a sense of discovering and exploring these spaces on our own, no matter how many times we come back to them. The shadowy streets of Gypo Nolan's Dublin in The Informer, the merciless desert that swallows up The Lost Patrol, are places we visit with a guide, always reminding us what these environments "mean".
The streets of Tombstone in My Darling Clementine, the unfinished church on the edge of town, the maze of the O. K. Corral, are every bit as charged with meaning and significance, but Ford lets us tease them out for ourselves -- he lets us inhabit them at our ease, until the places seem to speak to us in their own voices.