When 16-year-old Matt Logan and his friend Danny Duggan run away from an orphanage, they go west. There, they meet Jim Bridger and become fur trappers. But the market for beaver plews dies out, and the two friends take on jobs as wagon train guides. One of the trains Matt picks up began its journey in St Louis, led by widower Cody McNair. Cody was a well experienced leader, having once been the captain of an ocean-going sailing ship. His adult son and daughter, Jared and Ellen and their daughter Emma Joyce, make the trip with him. Also a part of the wagon company is the Baker family, Lon, his wife Norma, and their eight-year-old daughter, Precious. On the journey west, they rescue two travellers from other trains - tension develops with some of the members of the train, but Cody keeps everything in check as the train endures the rigors of travel. Five months and ten days after leaving St Louis, the train reaches its final destination of Oregon City, Oregon.