Colorado Sundown is a black and white 1952 American Western film directed by William Witney.

Rex jumps on and stops the stage, rescuing Jackie (Mary Ellen Kay) and Mattie (Louise Beavers).

Troubles arise when Jackie and Slim find they are inheriting a third share of a ranch along with Carrie Hurley (June Vincent) and her brother Daniel (Fred Graham).

The next day Carrie persuades Slim and Jackie to sell their portion of the ranch because of supposedly infected trees but Rex shows and stops the sale.

Stoker convinces some of the ranchers to sell but Rex is suspicious and writes to the forest service.