Rio Grande is third in John Ford's cavalry trilogy (following Fort Apache and She Wore a Yellow Ribbon). It's the least of the three, because the story gets bogged down in a superficial exploration of the relationship between John Wayne's character and his estranged wife, played by Maureen O'Hara. More interesting is the character that forces them together: their son, who has just enlisted in the United States army and finds himself under the command of his father, who he hasn't seen in fifteen years.

As with many John Ford westerns, Rio Grande incorporates several now familiar plot elements, but the ingenuity of the film lies not so much in the tale as the bittersweet historical picture it paints of changing times. While filmed in black and white, Rio Grande could scarcely be more colorful.