In its sixty plus years of film history, this site has posed as Tombstone, Arizona and Dodge City, Kansas. It has stood in for the rolling hills of Montana and the dusty streets of Laredo. Movie-goers have been fooled into mistaking it for the Royal Gorge of Colorado, the Ozark Mountains, Albuquerque, New Mexico, and Tom Sawyer's Missouri. Producers have even passed it off as 13th century China, colonial Salem, and the island of Java.
What is it? It's the Paramount Ranch, and its located in the hills just a few miles northwest of Los Angeles.
The streets were also filled with the numerous Hollywood stars who made movies here at Paramount Ranch, including Gary Cooper, John Wayne, Randolph Scott, Cary Grant, Henry Fonda, Alan Ladd, Burt Lancaster, Roy Rogers, Kirk Douglas, William Holden, Bob Hope, Jack Benny, Fred MacMurray, Charles Laughton, Glenn Ford, Robert Cummings, Basil Rathbone, Charles Ruggles, Cornel Wilde, Eddie Bracken, Joel McCrea, Ray Milland, Walter Brennan, Claude Rains, Robert Preston, James Garner and Warren Beatty. Actresses who worked along side them at the Ranch included Lucille Ball, Barbara Stanwyck, Marlene Dietrich, Jane Russell, Helen Hayes, Susan Hayward, Paulette Goddard, Betty Hutton, Rhonda Fleming, Polly Bergen, and Diane Keaton.
There were far too many movies made at the Ranch to list here, but some of the more notable ones included: "Paleface" (1948) and "Son of Paleface" (1952), "Gunfight at the OK Corral" (1957), "Fancy Pants" (1950), "The Virginian" (1946), "Whispering Smith" (1948), "The Forest Rangers" (1942), "Miracle of Morgan's Creek" (1944), "The Perils of Pauline" (1947), "Geronimo" (1939), "The Streets of Laredo" (1949), "Buck Benny Rides Again" (1040), "Ruggles of Red Gap" (1935)," "Gunsmoke" (1931), "The Plainsman" (1936), "Hopalong Cassidy Returns" (1936), "Wells Fargo" (1937), "Union Pacific" (1938), "The Adventures of Marco Polo" (1938), "The Adventures of Tom Sawyer" (1938) and "Reds" (1981).
http://www.seeing-stars.com/Studios/ParamountRanch.shtml 
Movie Locations, Studios 
