The race is on as the Central Pacific and Union Pacific Railroads lay down track across the U.S. bringing east and west together. Jacob Wheeler's one son, Abe, joins the railroad crew, while his other son Jacob Jr. becomes a scout for the army. Jacob's daughter Margaret and her photographer husband are captured by the Cheyenne, but her Lakota heritage saves them and they are adopted by the tribe. When the village is attacked by overzealous U.S. soldiers, many are murdered. Witnessing the brutality, Margaret decides to stay with her Cheyenne family.