During the summer of 1947, 20th Century-Fox built a western fort set to be used during the filming of Fort Apache (1948). The fort set was located on a plateau above (and north of) Silvertown. See the aerial photo on my Corriganville overview page at http://a-drifting-cowboy.blogspot.com/2012/07/corriganville-movie-ranch-overview.html
The Fort Apache set later became home for the "Adventures of Rin Tin Tin, The" (1954) TV Series. The set was demolished in 1967.
Above is a photo of Henry Fonda (fort commander) in a scene from Fort Apache (1948).
In another still from Fort Apache (1948) Ward Bond disciplines wayward soldiers outside the guardhouse.
John Wayne, John Agar and Shirley Temple in a scene filmed at the officer's quarters in Fort Apache (1948).
The photo above gives us a look at the Fort Apache set as it appeared in Ambush (1949) starring Robert Taylor.
William Holden takes command in a scene from Escape from Fort Bravo (1953).
Gene Autry and Champ ride through Fort Apache in a scene from Indian Territory (1950).
Fort Apache officer's quarters in a scene from Wild Stallion (1952) -- starring Ben Johnson.
While the dugout cabin was not actually part of Fort Apache it often appeared in films featuring the fort. It was located in a side canyon a few hundred yards west of the fort set.
The Dugout Cabin as seen in a scene from "The Adventures of Rin Tin Tin" (1954) TV Series.
Jennifer Jones (above) standing at the entry of the dugout in a scene from Duel in the Sun (1946).
Above Charles Starrett rushes bad guys hiding in the dugout in a scene from Renegades of the Sage (1949).
For more information about the Chatsworth filming locations visit http://www.cowboyup.com/ and learn about my books: Rendezvous at Boulder Pass: Hollywood's Fantasyland © 2010 (ISBN: 978-0-615-21522-8) and Reel Cowboys of the Santa Susanas © 2008 (ISBN: 978-0-615-21499-3)