If the chief female had not been called "Belle Starr," which was the name of a real person in the annals of the West, this would have been more in line with the rest of the Hoppy series. But that's a very minor problem.
Playing La Starr is an obvious stage actress, Natalie Moorhead. Because she's an obvious city slicker, she should not have been cast as a long-time Westerner; but her character could more easily have been a fairly recent immigrant. Still, only a very minor problem. Suspend your disbelief.
And enjoy William Boyd as Hopalong Cassidy. Boyd was undoubtedly one of the very finest actors to play the lead in a Western series. There is a subtlety in his every move and gesture, in his facial expressions, that show that, if it hadn't been for that ugly "news" paper error early in his career (when another William Boyd was arrested and our guy's picture ran), he might have been a huge mainstream star. He certainly deserved it. He certainly had the talent.
Russell Hayden gave a magnificent performance, surely one of his best. He was a good-looking guy and was a wonderful cowboy. His acting was uneven later, and he often sounded as if he had bad-fitting dentures, but here he was just perfect, a real pleasure to watch.
Dorothy Short gave another of her excellent performances, and George Hayes played his "Windy" character also to perfection. He too, by the way, was actually a city slicker -- well, sort of. In his bio at IMDb is this comment: "In real life he was the exact opposite of the characters he played on film. He was well read, well-groomed, serious and highly philosophical."
He reportedly did not even learn to ride a horse until he was 50, but few actors are more identified with Westerns than Hayes, and probably even fewer are and were more beloved. Any movie is better for his presence.
The other players were talented and the script-writer gave many of them a chance to shine -- which they do.
Paramount produced dusty and gritty Westerns, often showing the dusty and gritty ranch life, and often doing so better than other studios. Perhaps especially in the Hopalong series.
I highly recommend "Heart of Arizona," and you can find a very good copy at YouTube.
