My first Louis L'Amour. (My first Western novel, truth be told, unless you count some sci-fi quasi-westerns such as Mars -- The Red Planet by Mick Farren.) Won't be my last, though. In fact, as quick a read as this is--160ish pages, in dense typeface but relatively simple prose--I may make my next couple library stops just about L'Amour. (I'm still several books behind on my Challenge for the year.)
A couple nits to pick. He's clearly a gifted writer, but he's also extremely prolific, which means he was turning out novels at a breakneck pace during his heyday. His style is fantastic, but a bit more polish or care might have been taken here and there. In one paragraph late in the story he takes pains to point out that one character is 25 years old. Twice. Earlier in the novel he misuses "flaunt" where "flaut" should be, very much a novice kind of error. (This one at least might be chalked up to an editing or typesetting fault.)
Beyond the purely mechanical, there's really nothing to criticize. He uses the landscape capably, not exactly waxing poetic but definitely providing a strong sense of place. His understanding of the motivations of the characters borders on abnormal psychology.
This is classic good-versus-evil storytelling. The good guys are near-paladins. They make mistakes at times, but always of the tactical variety, and never of the moral or ethical. The bad guys are totally irredeemable, with death as the only suitable penalty. Set against a backdrop of encroaching winter and the threat of an all-out war with the Sioux, this is a tale of adventure on the high seas, star-crossed romance and ranch war (with a twist). I don't know whether it was written this way deliberately, but each scene is in handy bite size, in terms of action and dialogue, making this a very cinematic book (written at the height of the classic era of Western movies).