The third film in the Johns Ford and Wayne‘s ‘Cavalry Trilogy’ (following Fort Apache and She Wore A Yellow Ribbon) focuses on the competing forces of duty and family on the military life. Made as a quickie to satisfy studio bosses before Ford’s preferred, non-western, project The Quiet Man, it is nonetheless notable as the first of five collaborations between Wayne and Maureen O’Hara. Despite being a relatively minor entry on the CVs of all its major players and suffering from being a little rough and uneven, it’s still a John Ford western, and for the most part an enjoyable one.

Lieutenant Colonel Kirby Yorke (Wayne) is stationed at a Texan settlement on the Mexican border. With a reduced number of troops and constrained by a treaty with Mexico that prevents him from crossing the Rio Grande, Kirby and his charges are vulnerable to repeated Apache raids launched from the Mexican side of the river. When a new batch of recruits arrives, among them is his son Jefferson (Claude Jarman Jr.) whom he hasn’t seen for fifteen years and who lied about his age to enlist. Jeff is soon followed by his mother Kathleen (O’Hara), Kirby’s estranged wife who aims to take her son back home.

At this point, Wayne was settling into his medium-grizzled phase and his regular laconic drawl suits the weariness of a two-decade cavalry veteran. He’s enjoyably terse with young Jefferson, with the awkwardness of a son he’s never really known spiked with the necessary authority of a commanding officer. The first act is hugely enjoyable as the star takes something of a back seat as Jeff acquits himself well with his new comrades, with the Duke appearing every now and then to nod approvingly at the chip off the old block.

Things grind to a halt in the second act however with the appearance of Kathleen. The film is so keyed in to the father and son relationship that poor Maureen O’Hara, as strident and luminous as she is, drowns in a thankless role. The film attempts to create a tension that never rings true as Kathleen attempts to convince her estranged husband to sign Jeff’s discharge papers. By this point Kirby’s character has been firmly established so there’s never the merest hint of doubt whether he will choose family or duty. This leaves the second act adrift with an agonising inertia, not helped by interminable and sentimental musical interludes from the Sons of the Pioneers.

Thankfully, the film is saved by a rousing third act that never surprises but still impresses. Ford was a peerless director of horsebound action by this point, and he also had the considerable assets of Ben Johnson and Harry Carey Jr. in supporting roles; brilliant stuntmen with commensurate acting chops. The action is fluid, exciting and occasionally surprisingly intense.

70 years on, the characterisation of the Apaches themselves is non-existent, but that’s hardly unexpected even for westerns where the struggle between settler and indigenous people are the central focus. The enemy tribes in Rio Grande are merely a background threat in what is essentially a family melodrama; as much a homogenous existential threat as illness or deprivation.

While nowhere near an essential showcase for Ford or Wayne, and a complete waste of O’Hara, Rio Grande is still a generally enjoyable conveyor-belt western. If it’s been largely forgotten in recent decades, that’s because there are so many outright classics that have endured. It’s difficult so see who but the completist would seek it out, but no one who stumbles across it will be too disappointed.

Available on Blu-ray from Mon 6 Apr 2020