If one wanted to deconstruct this film visually, the task would not be hard — it practically deconstructs itself while you're watching it.
There are six types of images in the film, all radically different from each other in terms of how they were created:
1) Location shots, with unmanipulated images, including shots inside sets built on location in which you can see the actual location outside the doors and windows:
2) Studio interiors in which you can't see outside the door and windows, and which thus don't require false exteriors:
3) Studio exteriors, with artificially constructed “natural” settings:
4) Shots of people supposedly traveling on a raft down a river filmed against backscreen projections, with the foreground raft in the studio moving on gimbals:
5) POV location images looking forward from the moving raft shot on smaller-format cameras than the ones used for the rest of the film and blown up to fill the Cinemascope screen. (These are identifiable by their strikingly different grain structure from the other shots in the film.)
6) One single shot from a location on the river with a town on the shore of the river matted optically into the frame.
It's extraordinary that audiences of the time processed these disparate types of images as a coherent visual whole, but they clearly did. Contemporary reviewers of River Of No Return remarked on the spectacular location scenery and the exciting action scenes on the river without noting that the former were unmanipulated images and the latter tricked up in a studio.
What makes the contrasts between these disparate types of images starker than they might be is the stunning nature of the location shots. They are beautifully composed, give an impression of deep space, and often go on for considerable amounts of time in which complex and difficult actions occur on screen and which not infrequently involve elaborate camera moves.
All of these aspects of the shots made on location were characteristic of the director Otto Preminger's mature style and made him a darling of the Cahiers du Cinema set in the Fifties, influenced as it was by André Bazin's celebration of long takes and deep focus, as opposed to montage, as the primary and most potent tools of cinema.
Quite apart from theoretical considerations, Preminger's location images in River Of No Return are among the most beautiful and exhilarating in the whole history of Westerns. They are images that drawn you into the spaces of the scenes, imparting a sense of actually inhabiting them.
Robert Mitchum and Marilyn Monroe, the stars of the film, don't have a lot of screen chemistry, and Monroe delivers one of the stiffest and most awkward performances of her career, but when the two have a long magic-hour conversation by a campfire with a river rushing behind them, filmed in a single long take, performance hardly seems to matter.
The sheer cinematic beauty of the shot infuses itself into the actors, the dialogue, the narrative moment, the whole story of the film, so that we can accept these characters as people fated to become lovers, simply because they have inhabited this passage of sublime cinema. Aesthetic excitement is transmuted into emotional power. We believe that the characters will remember this moment forever, simply because we will.
Such scenes carry us through the backscreen passages, the artificial cave and the forest with the artificial trees. The latter become like dreams within the dream, and the dream of that actual fire beside an actual river at an actual sunset becomes the film's enduring reality.