As they ride in a stagecoach to their Arizona ranch, railroad magnate Arnold and his spoiled daughter Jessie argue about her recent involvement with a man in San Francisco. Strong-willed Jessie insists that she be allowed to return to San Francisco, while her father demands that she forget the affair. At the Arnold ranch, meanwhile, foreman Thatcher receives a telegram announcing Arnold's imminent arrival. Worried that his absentee employer will discover that he and his two ranch hands, Parnell and Clint, have been bilking the operation for years, Thatcher orders Clint and Parnell to murder Arnold on the stagecoach. The subsequent attack on the stage is detected by Dave Collins and Chito Rafferty, the owners of the stage line, who chase off Clint and Parnell before any harm is done. While the stage is stopped in Casco City, Jessie sneaks away from her father and buys some cowboy clothes, deciding to pose as a man in order to flee. Jessie then reboards the stage, which is now being driven by Dave and Chito, leaving her distraught father behind. Just outside of town, Clint and Parnell ambush the stage a second time, but upon discovering that Arnold is not on board, rob a strongbox containing $20,000 in cash. During the robbery, Jessie inadvertently unmasks Parnell for a moment, while Dave notes the brand on Parnell's horse. As Dave is about to drive back to Casco City, Jessie, who is determined to catch the next train to San Francisco, grabs his gun to stop him, but accidentally fires a round, causing the horses to run off with the stage. Now stranded in the desert, Chito, Dave, passenger Birdie, a saloon girl who is Chito's sweetheart, and an unhappy Jessie walk to Chito and Dave's nearby ranch. Later, at their ranch, Dave and Chito entrust Birdie to watch Jessie, while they ride to Casco City. In town, Dave spots Parnell's horse outside the saloon and, after brawling with him, hands him over to the sheriff. Dave and Chito then ride back to their ranch to retrieve Jessie for identification purposes, but learn that she has taken off on foot. Clint, meanwhile, reports Parnell's arrest to Thatcher, who decides that Jessie must be killed before she implicates Parnell. In the desert, Dave catches up to Jessie, lassos her to the ground and, without letting on that he is aware of her impersonation, spanks her. After a humiliated Jessie vows revenge on Dave, she is shot at by Clint and Thatcher. Hiding among some rocks, Dave exchanges gunfire with Clint and Thatcher, but it is Jessie who wounds Clint with a blind shot. Although the crooks ride off, Dave insists on remaining among the rocks until Chito finds them. Back in Casco City, Arnold finally deduces Jessie's impersonation and tells the sheriff and Chito that she must be found. While Chito, Arnold and the sheriff's posse head for the desert to find Jessie, Thatcher and Clint take advantage of their absence and break Parnell out of jail. Later that night, in their desert camp, Jessie is compelled to reveal her true identity to Dave in order to avoid a potentially compromising situation. She also tells Dave, who confesses he knew about the ruse from the beginning, about her San Francisco sweetheart. After Chito and Arnold finally locate them, however, Jessie announces to her father that she is now in love with Dave, and he encourages her to pursue the young rancher. When Jessie reveals her feelings to Dave, he questions her sincerity and insists that she is still a spoiled child. As the two argue, Parnell happens by and starts firing on them. Chased off by Dave, Parnell goes to the Arnold ranch and tries to claim his share of the strongbox money, but is told by the double-crossing Thatcher that the money was used to hide their embezzlement from Arnold. Parnell shoots Thatcher, then with Clint, takes Arnold hostage after Dave and Chito arrive and start firing at them. After agreeing to Parnell's hostage deal, Dave sneaks to the ranch house roof and jumps on the crooks as they lead Arnold outside. Dave and Chito eventually overwhelm and capture Clint and Parnell. Later, after Arnold blesses Jessie and Dave's engagement, Birdie shows off the wedding veil she bought in Tucson, causing confirmed bachelor Chito to drive off in alarm.