Outlaw Treasure (1955)

When two outlaw gangs team up to rob gold shipments, the U.s. Army sends their ace-troubleshooter, Dan Parker, to the area. Sam Casey, the mystery-man behind the gangs, kills Parker's father, and this induces his sweetheart, Rita Starr, to side with the law-and-order faction. An attempt by Casey to kill Rita is foiled by Parker, which leads to a widespread gun-battle.