Sully is appointed Indian agent to the Cheyenne and approaches it in an idealistic fashion. When the food intended for the tribe is diverted and illegal alcohol is plentiful, Sully becomes angry. He vows to discover the truth with the help of Dr. Quinn and her family.
Sam Lindsay, an older independent woman, decides to end her medical treatment and take off into the wilderness. Dr. Quinn accompanies her and learns from the journey. Myra Bing goes into labor and Colleen finds what she is capable of.
Colleen and Brian's biological father Ethan returns to town with a new wife, intending to take the children away from Dr. Quinn. The children don't want to go but a court hearing seems to work against Sully and Dr. Mike, who they consider their parents.
Colleen and Brian run away to keep their father from taking them away from Dr. Mike and Sully. After they are found it's discovered Colleen has developed pneumonia. Dr. Mike realizes she has to let them go to save them.
Ah abrasive Dr. John Porter arrives in town after hearing of the discovery of dinosaur bones. After learning they were found in a sacred Indian burial ground, he proceeds to spoil grave sites under the protection of the US Army. Cloud Dancing and the Cheyenne retaliate by taking the remains of the white settlers.
When Dr. Mike and Sully hear there is trouble for the Cheyenne at their new home, they travel there with Cloud Dancing only to find the whole tribe was massacred. Dr. Mike is devastated after the massacre because she felt she should have stopped it.
While on his way to resign as Indian Agent, Sully discovers Loren badly injured in the wilderness and must battle his own despair in order to save him. Meanwhile, Dr. Mike is worried about Brian who is consumed with his efforts to build a flying machine.
Dr. Mike and Sully go to Rev Johnson for a honest discussion regarding their upcoming marriage.After originally agreeing they have no conflicts, the couple begin reliving their past difficulties via prior show clips since they first met.
The town of Colorado Springs is preparing for an event of a lifetime, the marriage of Sully and Dr. Mike. Unexpected guests include Dr. Mike's mother Elizabeth Quinn and two of her sisters Rebecca and Marjorie. They have brought with them enough Boston finery to pull off a splendid society wedding. Meanwhile General Custer has put out a bounty on Cloud Dancing which could interfere with the wedding.
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 ...
Dr. Mike and Sully return from their honeymoon and begin unpacking at their new homestead. A Boston banker comes to town and stirs up controversy among the townspeople as the inevitability of progress ensues.
Loren convinces the town to pay a baseball team to visit for an exhibition game against the town's team. The two teams will share the ticket sales, but problems arise when it's discovered Loren didn't read the fine print.
As Dr. Mike becomes increasingly absorbed in her romantic life with Sully, Colleen, feeling rebellious, joins her school friends in dangerous and questionable escapades. When Brian also begins to feel ignored, Mike and Sully realize how important it is to balance their new life.
Elderly Abner Foley comes to town looking for alternative treatment and a very friendly dog adopts Jake Slicker. The rest of the town looks forward to the costume party but first Brian must face a very big fear.
Dr. Mike injures herself after the other women have turned back on their quest to climb Pike's Peak. Sully steps in for his wife on the council to thwart Jake and Preston's casino plans. Grace, Myra, and Dorothy change their minds and head back up the mountain.
As the community prepares to celebrate Thanksgiving, Dr. Mike and Sully become anxious with their inability to conceive. As the couple try to get used to the idea of not having a baby, Jake becomes depressed about being alone.
Dr. Mike and her family receive an unexpected gift from Boston, a small poodle unsuited to life on the frontier. Brian has his first crush on Sara, Preston is embarrassed by a painful kidney stone, and the Reverend plans a living nativity.