The last entry in the John Ford - John Wayne Cavalry Trilogy, Rio Grande is regarded by many observers as the best of the three. Wayne stars as Lt. Col. Kirby Yorke, whose devotion to duty has cost him his marriage to his beloved Kathleen (Maureen OHara). When Yorkes son Jeff (Claude Jarman Jr.) is assigned to his fathers post, Yorke is determined not to afford any preferential treatment to the boy-nor to exhibit any sign of love and affection. Sensing Jeffs heartache, Troopers Tyree (Ben Johnson) and Boone (Harry Carey Jr.) virtually adopt the boy, acting as surrogate parents. Yorkes resolve to remain oblivious to personal feelings is further tested when his estranged wife Kathleen arrives at the post, the better to look after her son-and possibly to buy back the boys enlistment. Kathleen has been out of Yorkes life ever since the Civil War, when, under orders, Yorke and his second in command Sgt. Major Quincannon (Victor McLaglen) burned down Kathleens familys plantation. After an attack by the Apaches, Yorke orders the posts women and children to be moved to safety. He further orders that Jeff lead the caravan to the safer post. Anxious to participate in the upcoming battle against the Apaches, Jeff resents his fathers command; but Kathleen understands, and her love for her husband is rekindled. Jeff is later given an opportunity to prove his courage by rescuing a wagonload of children from the Indians. Before the long-anticipated reconcilation scene between Yorke, his wife and his son, there are several peripheral plot complications, many of these involving a murder charge hanging over trooper Tyrees head. Though Rio Grande turned out to be one of John Fords most successful films, the director had initially refused to make it, acquiesing only after Republic promised him that hed be permitted to film The Quiet Man once the cavalry picture was in the can. In addition to the expected cadre of John Ford regulars- Wayne, OHara, McLaglen, Johnson, Carey, Grant Withers, Ken Curtis, Jack Pennick et. al.--Rio Grande serves as the film debut for John Waynes son Patrick. James Kevin McGuinness adapted his screenplay from the James Warner Bellah story Mission With No Record. ~ Hal Erickson, All Movie Guide