Director Otto Preminger's only western, River of No Return is set in Canada during the 19th century Gold Rush. Farmer Matt Calder (Robert Mitchum) is released from prison after serving a sentence for shooting a man in the back to protect a friend.
He arrives in a small town to retrieve his young son, Mark (Tommy Rettig), who has befriended a sultry saloon singer, Kay (Marilyn Monroe). Matt is also friendly with Kay, and thanks her profusely for looking after Mark, but distrusts her paramour, Harry Weston - a gambler with the morals of an alley cat.
Matt and Mark return to their rural homestead, but soon glimpse Kay and Harry on a sinking raft, apparently en route to make good on a gold claim; Matt rescues the two of them, but doesn't count on Harry doing an about face, beating him up, and stealing his horse and gun; Kay stays behind to look after Matt.
Meanwhile, the Indians go on the warpath, and the defenseless trio decides to stay safe by abandoning their farm; however, this means building and taking yet another raft, and en route, the son - thanks to Kay's doing - is unexpectedly disillusioned about the father's original crime.
Moreover, as Matt approaches town, he begins to plot a decisive revenge against Harry.