This is a very formula Western.
The formula is the same one used today. Since about 1950, the formula has been heavily in favor of "outlaws turning hero". This mentality didn't "creep" into the culture. It was slammed into the subconscious and the conscious of every American who watched more than ten Westerns in a life time. That's how brazen the formula was.
So, this is the biggest of clichés, and we get the most stereotypical characters you'll ever find in an old Western.
Still, the scenery and action works wonders to keep it from being dull. There are two women. The plain Jane one is nasty and hateful, and we can see her "reformation" a mile away. The other one is a hot Mexican woman, and her romance with the Army officer is the better and fresher story of the two romances. The romance of the vixen and the outlaw is so cliché filled that it was already a groaner in the sixties, so I expect it wasn't fresh in 1957 either, especially when one sees that this has been the standard since about 1950.
So, this is actually "fluff", and not just "fluff", but definitive "fluff". No dimensions here at all. Nothing fresh, but nice action and scenery.