The year is 1868. A young Native American boy, a Wintu, leaves the reservation in the Mendocino County of California to search for his father, a white man, who had been taken in by the tribe after an attack by a bear. His journey, and that of his sister, a companion from another tribe, and a young Chinese "Daughter of Joy," follow the Iron Trail of the First Transcontinental Railroad as it is completed, and as its Last Spike is driven into the hearts and minds and hopes of America's indigenous people.