The Tall Stranger (1957)

Union vet Ned (Joel McCrea), gunned down by some tough cattle rustlers, comes to in a wagon train under the care of kindly widow Ellen (Virginia Mayo). But, as he heals, he senses all is not well, and realizes that the suspicious men leading the train are taking the settlers to land owned by his estranged half-brother, an embittered man who will shoot any strangers. Ned then tries to warn the pioneers, while preparing to face the sibling who harbors a deep-seated grudge against him.