Boss Spearman (Robert Duvall), Charley Waite (Kevin Costner), Mose Harrison (Abraham Benrubi), and Button (Diego Luna) freegraze their cattle across the vast prairies of the West, sharing a friendship forged by a steadfast code of honor and living a life unencumbered by civilization. When their wayward herd forces them near the small town of Harmonville, the cowboys encounter the corrupt Sheriff Poole (James Russo) and kingpin rancher Denton Baxter (Sir Michael Gambon), who govern the territory through fear, tyranny, and violence. Boss and Charley find themselves inextricably drawn towards an inevitable showdown, as they are forced to defend the freedom and values of a lifestyle that is all too quickly vanishing. Amidst the turmoil, life suddenly takes an unexpected turn for the loner Charley when he meets the beautiful and warm spirited Sue Barlow (Annette Bening), a woman who embraces both his heart and his soul.