The Civil War started in the spring of 1861. In the spring of 1862, Jeb and Doris Whitney head west with their youngest son, Josh, leaving their older son, Joe, and his bride in possession of the Ohio farm. Jeb and Doris are seeking a new homestead for Josh, but their move is also contrived to prevent Joe from joining the Union Army. Doris dies of undulant fever just short of the beginning of the Oregon Trail at Westport, Missouri. Jeb becomes a despondent alcoholic and Josh desperately enlists a couple of new-found friends in Westport in trying to bring his father back to normal. Jeb clashes with Mr. Blue, a mean, gun-slinging card shark that wiser men avoid, and is severely wounded in the resulting shoot-out. Several days later, Josh is the sole witness as a cheated card player confronts Mr. Blue at gunpoint one night and is killed by Mr. Blue. Josh is the only one who can prove that Mr. Blue is innocent of murder by the standards of the day. But Josh finds that the whole town wants Mr. Blue hung. He has killed six men, bullied everyone in town, and threatens to kill Josh and his father when he gets out of jail. Josh makes a decision contrary to his own conscience. Jeb sobers up and marries the lady who nursed him back to health after the gunfight. Josh wants to continue west and finds his opportunity when a preacher and his wife come through Westport, seeking a location to start a new church. Josh joins them, thinking they will need his help to survive and prosper, but also finds that they are determined to practice non-violence in this violent land. By the time the preacher and his wife reach Fort Laramie, Josh has saved them from several outlaws and an Indian raid, but they have cast him out as an agent of the devil. Josh wins the friendship of Lewis, a small, but very tough mountain man who serves as a scout for Fort Laramie. On a trip into Sioux country, Josh finds that Lewis has a Sioux wife and children that he loves more than he wants the Army to know. They join a Sioux buffalo hunt and Josh runs afoul of White Hawk, a Sioux warrior, due to the mischievous flirting of an Indian maiden. By the time he and Lewis return to Fort Laramie, Josh regards Lewis as a best friend and has learned some sympathy and respect for the Sioux. Lewis predicts that it's only a matter of time before the Army controls all Indian lands, but is doing all he can to keep the peace and delay that day. The preacher's wife is caught by a band of Indian raiders and brutally killed. Abandoning non-violence, the preacher is at Fort Laramie, doing his best to stir up an all-out war. A shipment of rapid-fire rifles is being sent to Fort Laramie. Lewis worries about the rifles and the "sword swinging" officer bringing them. Kirby Twine, a young greenhorn, convinces Josh to go with him into the Big Horn mountains in Crow Indian territory in search of the source of a sample of gold ore he has. Deep in the mountains, Josh realizes how foolish they are and discovers that Kirby's "gold ore" is fool's gold. Kirby is eager to continue the search until they are caught at a severe disadvantage by a Sioux band that has come to raid the Crows. White Hawk is the leader of the Sioux band, and Josh negotiates successfully at gunpoint. Back at Fort Laramie, Josh is present when the shipment of rapid-fire rifles arrives and the crates prove to contain only sand and a few token Indian arrows. In the official inquiry that follows, the conclusion is that the rifles were stolen by Indians with the aid of Confederate spies or soldiers. Some time later, Josh realizes that Lewis is the only man he knows who could have led Indians on such a mission. Talking it over with Lewis in an oblique way, Josh is given a reason to keep the secret. The preacher enlists the aid of a self-serving scout, La Croix, to help him punish the Indians, but the preacher is apparantly killed while on a mission with La Croix. Later, Lewis kills La Croix in a shoot-out, and the