Fred C. Dobbs and Bob Curtin, both down on their luck in Tampico, Mexico in 1925, meet up with a grizzled prospector named Howard and decide to join with him in search of gold in the wilds of central Mexico. Through enormous difficulties, they eventually succeed in finding gold, but bandits, the elements, and most especially greed threaten to turn their success into disaster.

Retired, wealthy sea Captain Jame McKay arrives in the vast expanse of the West to marry fiancée Pat Terrill. McKay is a man whose values and approach to life are a mystery to the ranchers and ranch foreman Steve Leech takes an immediate dislike to him. Pat is spoiled, selfish and controlled by her wealthy father, Major Henry Terrill. The Major is involved in a ruthless civil war, over watering rights for cattle, with a rough hewn clan led by Rufus Hannassey. The land in question is owned by Julie Maragon and both Terrill and Hannassey want it.