Salamanca Tree Hiddle (called Sal throughout most of the book) is packed and moves with her widow father from Bybanks, Kentucky to Euclid, Ohio where the woman he proposes to marry, Margaret, lives. Sal doesn't like her very much, and when her grandparents plan to take a road trip to her mother's (and their daughter's) graveside in Lewiston, Idaho, she goes with them and relates the story of her and her friend in Bybanks, Phoebe Winterbottom.
The story, which alternates with the present-day setting of the text, helps Sal to achieve closure with her mom and accept a new life with her new and extended families.