The Great Sioux Uprising [1953] [DVD]

Joan Britton, improbably gorgeous frontier horse dealer, and the much less scrupulous Stephen Cook are friendly competitors supplying horses to the Union Army in Wyoming Territory during the Civil War. Southern general Stand Watie, a Cherokee, is rumored to be in the area to stir up the Sioux against the Union, when Cook picks this worst possible moment to steal a herd of Sioux horses. Enter ex-army doctor Jonathan Westgate, who becomes Cook's rival for the love of Joan, opposes his crooked activities...and who alone can prevent a new Indian war. ~ imdb