Bolstered by the long-awaited arrival of the railroad, the citizens of Colorado Springs busily prepare for the biggest social event in the town's history, the wedding of Dr. Mike and Sully. The first train carries some surprise visitors, Dr. Mike's mother, Elizabeth, and sisters Marjorie and Rebecca, who have unexpectedly traveled all the way from Boston for the occasion. However, their elaborate wedding plans threaten to ride roughshod over the townsfolk's more homespun arrangements. Sully, meanwhile, is crestfallen to learn that Gen. Custer has placed a bounty on the head of his close friend Cloud Dancing, who he had planned to have as his Best Man.