This pioneer epic shows the hardships and tribulations of settlers heading west on the Oregon trail.
Many settlers meet at the Mississippi River to join a wagon train west. Scout Breck Coleman (John Wayne) first wants to track down the two men who murdered his trapper friend for his wolf pelts; but he takes the job when he learns that one of the suspects is the wagonmaster Red Flack (Tyrone Power, Sr.). Coleman promises to lead the Camerons and others to a valley north of Oregon he describes in glowing terms. On the way he and Ruth Cameron (Marguerite Churchill) eventually fall in love. She mistakenly accuses him of murder before the group; but he is innocent and later forgives her, saying, "We all get off on the wrong trail once in a while." The train of many wagons trudges through the sandy desert and circles up to fight off attacking Indians, followed by a scene of grief for those killed. Coping with the rain and mud is realistically portrayed. It's very rough going to make ten miles a day, and the Rocky Mountains are still ahead.
Amid the snow Flack gets the other murderer Lopez to stab Coleman with the dead man's knife; but he escapes and now knows for sure who the murderers are. They flee, and Coleman is persuaded to keep his promise before returning to follow their trail. When the trail seems roughest, Coleman gives a rousing speech about those who have blazed trails all the way from England, into Kentucky, and now across the western plains. Even the spirits of those who have died lead them onward. Coleman goes back to help the Camerons, who stopped because they lacked horses. He gets them to go forward in only one wagon. Finally the promised valley is in sight, and Coleman can go back to trail the murderers. Flack leaves Lopez behind in the snow, and Coleman finds him dead, showing how the vicious betray each other as compared to those who help each other. Then after Flack shoots at him, Coleman stabs the murderer with his knife. In the end the settlers have built a log cabin in the redwood forest, and Coleman arrives to be welcomed into the arms of Ruth Cameron. The final scene shows the grandeur and majesty of the giant Sequoias.
This big western portrays the challenges of pioneering and gives the audience a hero whose courage, capability, and determination can be admired even though his sense of "frontier justice" leads him on the trail of personal revenge in which he takes the law into his own hands and kills a man.