This is a fairly routine oat-opera of the "manifest destiny" subgenre. It has a stellar cast that is underused, and even the supporting cast is first-rate (the excellent Akim Tamiroff and Lynne Overman play the wisecracking bodyguards, and Brian Donlevy has one of his crafty kingpin roles -- by way of comparison, recall Donlevy and Tamiroff in "The Great McGinty"). The special effects are surprisingly hokey and it appears that fairly little of the movie was actually shot outside. And the sensibilities of the time show through, when one of the bad guys casually and cold-bloodedly murders an Indian, and the good guy does nothing more than punch the murderer a few times. While this might be historically more accurate than modern portrayals, it's still appalling to watch.
All that said, the movie is still entertaining. The dialogue is often more sophisticated than you'd expect, and this cast makes the most of anything they've been given. And you do get to see a couple of scenes of people laying rails and some shots of cool old steam trains. However, if you don't like old movies, don't bother with this one (if you know anything about old movies you can guess the details of the plot within 10 minutes of the beginning of the movie, and you'll get almost everything right).
All that said, the movie is still entertaining. The dialogue is often more sophisticated than you'd expect, and this cast makes the most of anything they've been given. And you do get to see a couple of scenes of people laying rails and some shots of cool old steam trains. However, if you don't like old movies, don't bother with this one (if you know anything about old movies you can guess the details of the plot within 10 minutes of the beginning of the movie, and you'll get almost everything right).