Gold miners flood wheat fields, causing a bitter economic, social, and legal battle that divides a family.
In 1877 in the Sacramento valley gold miners flood wheat farmers. At a bar Lance Ferris (Tim Holt) gets into a fight, but Jared Whitney (George Brent) ends it by hitting Lance to save him. Jared meets Lance's sister Serena Ferris (Olivia de Havilland), who has her own orchard. Jared is an engineer and the new superintendent of the Golden Moon mine, where he finds insolent foreman Slag Minton (Barton MacLane) not working and slugs him. Their hydraulic power sends mud into the wheat fields. Ralph Ferris (John Litel) sells his land to his brother Chris Ferris (Claude Rains) for $100,000 so he can go into gold. Jared visits Serena in her orchard and shows her how to irrigate. As Chris tallies his harvest, Lance asks his father for a loan that is denied. Lance tells Serena he is going to San Francisco.
McKenzie (Russell Simpson) sees his house washed down, killing his wife and child. At a meeting of farmers Chris counsels law and order instead of violence first. Chris sees Jared and Serena kiss and tells Jared not to come there anymore. Jared goes to San Francisco to ask for a dam; he finds Lance and meets his aunt Rosanna Ferris (Margaret Lindsay), daughter of his boss Harrison McCooey (Sidney Toler). He approves the dam, because it will stop water to two other mines. Jared writes to Serena, who learns her father got Jared to go away. Golden Moon mine stock goes up as the others go down. Serena visits Rosanna, and Jared takes her out. Lawyer Crouch (Robert McWade) tells Ralph of the ranchers' suit against the Golden Moon. McCooey reacts by sending men. Serena tells Jared that the miners are wrong and warns him. She tells Lance that she is going home.
In court Chris argues for the injunction to protect farmers from the miners' mud. Crouch contends that gold supplies more economic progress. The injunction is granted. McCooey orders Jared to defend the mine with guns, but Jared refuses to kill. Foreman Minton is appointed. After a server is intimidated, Lance volunteers to serve the injunction. Minton tells Jared that he is fired. Lance rides in and is shot by Minton. Jared leaves with his body. As he dies, Lance tells Serena that Jared tried to warn him. Chris and McKenzie lead men with guns into a battle; but Jared asks Chris for thirty minutes and takes dynamite to blow the dam as Minton's men shoot at him. Minton wounds Jared. The dam breaks and floods men. Jared rescues Chris, and Minton is killed as mine equipment is destroyed. The California Supreme Court upholds the farmers. In the final scene Jared and Serena see the future in fruit.
This archetypal western plot is set in a historic and economic context that gives deeper meaning to the conflict. The environmental damage of greedy mining is contrasted to the patient farming of nourishing food.