The highly melodramatic western begins with St. Louis resident Katharine Hepburn marrying New Mexico cattleman Spencer Tracy after a short courtship. When she arrives in "Salt Pork, NM" she finds that her new husband is considered by the locals to be a tyrant who uses force to keep homesteaders off the government owned land he uses for grazing his cattle--the so-called Sea of Grass. Hepburn's character, Lutie, has difficulty reconciling her husband's beliefs and passions with her own, and eventually leaves him just long enough to conceive a child with her husband's moral enemy. Two years later, in the midst of a crisis, her husband discovers her infidelity and forces her to leave--without her two children (husband's daughter and other man's son).