When a wagon train of weary Kansas immigrants led by the crafty and verbose Joshua Richardson arrives at Bear Creek, Breckinridge Elkins is “volunteered” by his pap to guide them to a more suitable settlement in Bowie Knife Canyon, Arizona. Reluctantly, Breckinridge takes on the task, despite his suspicion that the settlers are unfit for frontier life. Along the way, they encounter trouble in the outlaw-infested town of War Smoke and learn that a bandit leader named Señor Gonzales Zamora already claims the canyon.

Complications multiply when a second wagon train led by none other than Breckinridge's equally headstrong cousin Bearfield Buckner also stakes claim to the valley. Before the cousins can settle the matter with guns, they learn that Zamora’s gang is preparing to attack both camps. After a full-scale brawl, a daring rope-climb assault, and some spectacular frontier justice, the outlaws are scattered or dead. Ironically, the two immigrant groups—originally terrified and useless in a fight—decide to settle the canyon together in peace, leaving the combative cousins disgusted with the triumph of pacifism.