Rio Grande is a 1950 film and the third installment of John Ford's "cavalry trilogy", following Fort Apache (1948) and She Wore a Yellow Ribbon (1949). John Wayne stars in all three films, as Captain Kirby Yorke (York) in Fort Apache, then as Capt. of Cavalry Nathan Cutting Brittles in She Wore a Yellow Ribbon, and finally as a promoted Lieutenant Colonel Kirby Yorke (York) in Rio Grande.

Ford wanted to make The Quiet Man first, but the man pulling the purse strings at Republic Pictures, Herbert Yates, insisted that Ford make Rio Grande first, using the same combination of Wayne and Maureen O'Hara; Yates didn't feel that the script of The Quiet Man was that good, and wanted Rio Grande out first to pay for The Quiet Man. (To Yates's surprise The Quiet Man, on its eventual release in 1952, would become Republic's number one film and become a favorite of Ford/Wayne fans.)

Barker is after the Andrews ranch and kills Bart Andrews. But Bart had sent for Cliff and Cliff now arrives and takes over the fight against Barker. To get the necessary hands to drive Andrews' herd to market, Cliff makes a deal with Barker saying hew will give him half the money collected. Both Cliff and Barker then make plans to double-cross the other when the cattle are sold. Written by Maurice VanAuken

Rio Grande takes place after the Civil War when the Union turned their attention towards the Apaches. Union officer Kirby Yorke is in charge of an outpost on the Rio Grande in which he is in charge of training of new recruits one of which is his son whom he hasn't seen in 15 years. He whips him into shape to take on the Apaches but not before his mother shows up to take him out of there.The decision to leave is left up to Trooper Yorke who decides to stay and fight. Through it all Kirby and Kathleen though separated for years fall back into love and decide that it's time to give it another try. But Yorke faces his toughest battle when his unorthodox plan to outwit the elusive Apaches leads to possible court- martial. Locked in a bloody Indian war, he must fight to redeem his honor and save the love and lives of his broken family Written by Christopher D. Ryan