In 1930, in the heart of East Texas oil country, unemployed wildcat oil well drillers Delbert Lane, Tex Warren and Duke Massey roam the state looking for work. Soon after arriving in Kilmer County, Duke meets newspaper editor Matt Brady and Matt's attractive daughter Julie. Julie tells Duke that there is plenty of oil under Kilmer County but that no one has dug deep enough to find it. Though Julie is Tex's old sweetheart, Duke pursues a romance with her. Julie later rejects Tex's marriage proposal, telling him that she does not want to marry an oil man or a newspaperman like her father because they live unsettled, transient lives. Always searching for a way to make an easy profit, Duke devises a plan to fleece the people of Kilmer by having them invest in oil drilling that is unlikely to yield oil. After drilling for several days without striking oil, Duke declares the well dry and makes preparations to leave town with the remainder of the investors' money. Tex, however, refuses to abandon the project without fulfilling his obligation to the people of Kilmer, and insists on digging another thousand feet. Tex demands that Duke turn over his share of the money to complete the drilling, and a fistfight ensues when Duke accuses Tex of using the drilling to impress Julie and win her affections. Duke leaves town for West Texas, but Julie, who is in love with Duke, follows him and offers to marry him. Julie and Duke wed, while Duke earns little money building wells in West Texas, Tex and Delbert, who have continued their digging in Kilmer, strike oil. Later, Julie realizes that Duke has been abusive to her because he is too proud to accept money from her and is uncomfortable with newly acquired oil wealth. Months later, Julie gives birth to baby boy, and Duke finally strikes oil, making him a millionaire. When the governor of Texas and other legislators meet at Duke's house to discuss oil matters, Duke persuades them that it is time to create laws that will force all oil producers to pro-rate the amount of oil they take from each well. Though he does not reveal his motives to the legislators, Duke knows that such a law will badly hurt Tex. Tex, however, decides to disobey the new law and continue producing oil at full capacity. Many independent oil drillers resort to violence against the state oil inspectors in order to keep their wells running. Julie leaves Duke when the militia is sent to Kilmer as a result of Duke's heartlessness in enforcing the law. Duke eventually realizes his foolishness, and goes to Kilmer to settle his differences with Tex. Duke and Tex engage in a bruising hand-to-hand fight, then having cleared the air, resume their friendship.