Set in the Northwestern United States in 1875, the film focuses on taciturn widower Matt Calder (Robert Mitchum), who has recently been released from prison after serving time for killing one man while defending another.

He arrives in a boomtown tent city in search of his nine-year-old son Mark (Tommy Rettig), who was left in the care of dance hall singer Kay (Marilyn Monroe) after the man who brought him there, as Matt had arranged, abandoned him.

Kay's fiancé, gambler Harry Weston (Rory Calhoun), tells her they must go to Council City to file the deed on a gold mine he won in a poker game.

Along the way, they are forced to deal with such things as the Rapids, Kay getting soaked and chilled, a mountain lion attack; gold prospectors Sam Benson and Dave Colby, who are after Harry for stealing their claim; and a second Indian war party.

Otto Preminger was preparing for the opening of The Moon Is Blue when 20th Century Fox executive Darryl F. Zanuck assigned him to direct River of No Return as part of his contract with the studio.

Much of it would be filmed in Banff and Jasper national parks, Lake Louise in Alberta and the Salmon River in Idaho where the story actually takes place.

During their time there, Rubin grew fond of the director and began to feel that rather than viewing it as a contractual obligation, Preminger had a real interest in making the film.

[8] Rubin scheduled twelve weeks of preproduction, during which Monroe rehearsed and recorded the musical numbers written by Ken Darby and Lionel Newman, and forty-five days for filming.

She insisted on taking her client aside and giving her direction contrary to that of Preminger, and she had the actress enunciating each syllable of every word of dialogue with exaggerated emphasis.

Zanuck commiserated with Preminger but, feeling Monroe was a major box office draw he couldn't afford to upset, he reinstated Lytess.

[11][12] During the difficult shoot, Preminger also had to contend with frequent rain, Mitchum's heavy drinking, and an injury to Monroe's ankle that kept her off the set for several days and ultimately put her in a cast.

Written by Alfred Newman, it's a rerecording of his original 1933 fanfare, with the extra few bars that play under the credit "20th Century-Fox presents A CinemaScope Production".

He felt the director had failed to capture the Western aura, had ignored key elements in the plot, and had perfunctorily directed action sequences, leaving them looking staged and static.

[20] In the United States 20th Century Fox released the film on Blu-ray disc on July 31, 2012 for the first time with the original theatrical trailer as the sole extra feature.

[21] Bosley Crowther of the New York Times observed, "It is a toss-up whether the scenery or the adornment of Marilyn Monroe is the feature of greater attraction in River of No Return ...

A sickening succession of rapids, churned into boiling foam, presents a display of nature's violence that cannot help but ping the patron's nerves.

"[22] Variety said, "The competition between scenic splendors of the Jasper and Banff National Parks and entertainment values finds the former finishing slightly ahead on merit, although there's enough rugged action and suspense moments to get the production through its footage.

"[23] TV Guide rated it 3+1⁄2 out of four stars, calling it "a simple, frequently charming, and beautifully photographed film blessed with fine performances and great teamwork from Robert Mitchum and Marilyn Monroe" and "an enjoyable, engaging little Western that never fails to entertain.