Moon of Bitter Cold begins in 1866 when the Civil War has ended, but the war in the west, with its bloody collision of cultures, is increasingly tense and dangerous. As the US Army builds more forts on the Great Plains and into the Wyoming Territory, the Plains Indians raid, attack, and skirmish, but to little effect. Then Red Cloud, a Lakota Sioux war leader, assembles more than 3,000 warriors, uniting the Sioux with the Cheyenne, Arapho, and Crow in order to make war on the white man. This is the only war that the western Indians ever win against the encroaching settlers.