This superb '50s western is what I term a "minor masterpiece". By that I do not mean that it is inferior, rather that its "B" status will inevitably always relegate it to side discussions when the "big" westerns are brought up. But a very convincing argument can be made that this, and many other '50s "B" westerns-including in my view almost all of the Audie Murphy ones-are the absolute pinnacle of the genre.
Other reviewers have given good accounts of the plot so I will instead mention: the marvellous cast (DeForrest Kelly was underused as a westerner-marvel at his performance); the tension that I think is due to the modest running time and the quick, simple scenes that just flow so naturally; great, bright colour (I loathe the dark modern movies); a second-to-none score from an age when there were great film composers; all the essential elements are here-the boy, the tortured hero, believable domestic tensions, the baddies-you just care about these characters.
Every time this appears on British TV I seem to watch it afresh and discover more subtleties.
Minor masterpieces are not that much more common than major ones. Do not miss this movie.