Here is an interesting article about the re-release of the movie Close Encounters Of The Third Kind for its 40th anniversary and how 8 movies influenced it including My Darling Clementine. It said: My Darling Clementine (1946)
There are conflicting reports on how Devils Tower was chosen for its iconic involvement in CE3K. More likely is the story of production designer Joe Alves choosing the location while driving around the West. But there’s also the claim that Spielberg wanted to use the natural monument after seeing it in My Darling Clementine. He really was interested in anything majestically akin to the landscapes of John Ford’s Westerns. Spielberg is said to have watched The Searchers over and over while making CE3K.
Perhaps he also was a fan of this Ford classic, which stars Henry Fonda as Wyatt Earp and Victor Mature as Doc Holliday in the story of the gunfight at the OK Corral. Maybe he’s fond of movies released in the year of his birth (I know I am, which is part of why I have a special interest in CE3K, having been born in 1977). There is another interesting connection between Spielberg’s movie and Clementine: Verna Fields, Oscar-winning editor of Jaws and daughter of Clementine co-writer Sam Hellman, worked on CE3K in an unofficial capacity as an editor and associate producer. https://filmschoolrejects.com/movies-to-watch-close-encounters-of-the-third-kind/