In the remote Chinook Pass area, Trooper Matt O'Brien of the Canadian Mounted Police helps a patronizing American woman with her broken-down car, then reports to his superior, Inspector "Mac" McGrath. To his dismay, Mac orders O'Brien to escort the woman, Kate Owens, to her uncle's place in Morgan's Post. While camping on the way, one of Kate's bags is stolen by a man on horseback. O'Brien pursues the thief and shoots him dead, but before he can retrieve the bag, two other men snatch it away. O'Brien is unable to catch the men and is annoyed to learn that the bag contained $20,000. As they near Morgan's Post, O'Brien and Kate, whose horse has gone lame, stop at a homestead to borrow a fresh mount. To O'Brien's surprise, the homesteader is Poodles Hanaford, a former circus entertainer who had written to Mac complaining that his creek had dried up and he had been shot at while trying to investigate the problem. When O'Brien and Kate arrive at Morgan's Post, her uncle, John Owens, is upset about the robbery, as he needs the money to pay his workers and buy timber land from a French-Canadian named Pierre. Later, O'Brien stops saloon owner Whitey Yaeger from beating his wife. O'Brien then brawls with Whitey, who unknown to him, is the leader of the gang that stole Owens' money, and is aided by Sgt. Means, the Mountie assigned to the area. Means, who has not sent a report to Mac in two months, assures O'Brien that he will investigate the robbery and explains that Hanaford's creek dried up naturally and he was shot at because he was trespassing on private property. Means then orders O'Brien to return to Chinook Pass. On his way back, O'Brien stops at Hanaford's and offers to go with him to the spring that is the source of the creek. As they are riding there, however, they are shot at by Whitey, who then flees. O'Brien deduces that his attacker has fled to Morgan's Post and goes to investigate. There, while O'Brien sneaks around Whitey's cabin, Mrs. Yaeger finds a metal handle in the ashes of a fire that her husband had built and deliberately tosses it in O'Brien's direction. After Kate confirms that the handle is from her stolen bag, O'Brien questions the frightened Mrs. Yaeger. Aware that Whitey is following them, O'Brien sets a trap for him and catches him. O'Brien takes Whitey, whose pockets are filled with cash, to Means, but Whitey insists that he won the money gambling. Once again, Means orders O'Brien to return to Chinook Pass, but before going, O'Brien offers to ride to the spring with Hanaford. On the way, they hear an airplane overhead and are shot at by Pierre. O'Brien outmanuevers Pierre, who is carrying cash and gold dust, then delivers him to the trading post. After instructing owner Morgan to guard Pierre, O'Brien returns to the spring, where he expects to discover a gold mining operation. Morgan, however, frees Pierre, who then plots with Whitey to kill O'Brien, but Kate overhears their plan and rushes to warn O'Brien. O'Brien once again traps and outshoots Pierre and Whitey, who races back to his cabin. There, the wounded Whitey is confronted by Mrs. Yaeger, who reveals that she found a body in a shallow grave near the cabin. Just as Whitey begins choking his wife, O'Brien rides up and shoots him dead. After Mrs. Yaeger tells O'Brien about the body, he instructs Morgan to inform Means that he is arresting Owens and taking him to Hanaford's. O'Brien then tricks the unsuspecting Owens into going to Hanaford's and there accuses him of conspiring with Pierre and the others to smuggle gold across the border. When Means arrives, O'Brien exposes him as an impostor, noting that the real Means, who was missing one of his fingers, is buried behind Whitey's cabin. After a brief gunfight, O'Brien kills or arrests all of the smugglers. Later, Kate, who has grown fond of the Mountie, rewards O'Brien with a long kiss.