The Fox (1921)

Santa Fe, a tramp, is saved from a jeering mob in the desert town of Caliente by Annette, the sheriff's daughter; and after adopting Pard he gets a job as porter in the bank. Santa Fe learns that the leading banker, Coulter, is in league with a band of outlaws, and when Coulter frames Dick Farwell, Annette's fiancé, Dick is suspected of robbery and is captured by the outlaws. Santa Fe saves the sheriff from death in a sandstorm but is himself captured; he escapes with Dick by a subterranean river and arrives in town in time to save the sheriff from a mob and to reveal himself as a special agent sent to catch Coulter. Aided by the U. S. Cavalry and a posse, he leads an attack on the outlaw stronghold and takes Coulter. Santa Fe wins the love of Annette.