There's a deficit of good, honest women in the West, and Roy Whitman (John McIntire) wants to change that. His solution is to bring a caravan of over 100 mail-order brides from Chicago to California. It will be a long, difficult and dangerous journey for the women. So Whitman hires hardened, cynical Buck Wyatt (Robert Taylor) to be their guide across the inhospitable frontier. But as disaster strikes on the trail, Buck just might discover that these women are stronger than he thinks.