In the late 1860s, Colonel Carrington and his command are assigned the job of constructing a chain of forts in the Sioux Indian territory - of Wyoming. Carrington recruits former cavalry scouts Jim Bridger and "Dakota Jack" Gaines to lead the project. Bridger and Gaines are friendly with Sioux Chief Red Cloud, and they feel a peace treaty with the Indians can be made. If an Indian war breaks out, the cavalry is depending on getting a new type of Springfield rifle. Bridger, Gaines and Gaines wife, Maxine, arrive at the fort for the conference. Gaines, in a drunken fit, tries to intimidate the Indians into signing a treaty. Chief Red Cloud threatens war if his territory is invaded by any troops building forts.