Gary Merrill heads the cast of the unorthodox western The Black Dakotas. The story is set during the Civil War, as President Lincoln tries to mollify the Sioux Indians in order to free up soldiers for more important fighting. Disguised as a Northerner, Brock Marsh (Gary Merrill) intercepts Lincoln's emissary and heads into Sioux territory himself, hoping to steal Union gold for the Southern cause, and to stir up an Indian war between the Sioux and the Dakotas, who have already cast their lot with the North. It soon develops that Marsh doesn't care who wins the war; he wants to abscond with the gold himself. Wanda Hendrix, who despite her divorce from Audie Murphy was still regularly employed in westerns, costars as the daughter of Southern spy Fay Roope, and the sweetheart of good-guy stagecoach driver John Bromfield.