20 Mule Team (1940)
20 Mule Team (aka Twenty Mule Team) is a 1940 American Western film about Death Valley, and Daggett, California borax miners starring Wallace Beery and Anne Baxter, and remains an extremely rare opportunity to watch Beery work with his similar-looking nephew Noah Beery, Jr., who played "Rocky" on television's The Rockford Files 35 years later. The movie was directed by Richard Thorpe and originally released in Sepiatone, a brown and white process used by the studio the previous year for the Kansas scenes in The Wizard of Oz.
More at Wikipedia.