This paper uses previously unpublished letters from Jean Renoir to give an in-depth account of the pre-production, production and post-production stages of The River (Jean Renoir, 1951). It focuses on the process of adapting the script from Rumer Godden's novel, the problems encountered shooting on location in India with inexperienced actors, inadequate equipment, untried technology (Technicolor, magnetic tape), plus the editing process and last minute writing of a voice-over. This paper outlines how these events determine the film's visual and aural style, and the pivotal role the film plays in Renoir's career.