An archetype is "a symbol, theme, setting, or character that is thought to have some universal meaning" in literature. One archetype that is used in Walk Two Moons is the element of story. Traditionally, stories are shared and passed on to help people understand things that are beyond comprehension. In the book, the reader comes to an understanding of Salamanca's mother's life and death through the interwoven stories of the death of Sal's mother, Sal's journey with her grandparents, and Phoeby's mother's temporary disappearance.
Another archetype in the book is the journey, or quest. Sal's mother embarks on a journey of self-discovery, from which she never returns, and Sal herself must undertake a journey with her grandparents to discover the truth about her mother's fate, and how it relates to her own life.
A third archetype in the story is home, both as a physical place and a state of being. Salamanca must leave the security and peace of her home in Bybanks in order to resolve her confusion and grief at her mother's leaving. Only after she discovers the truth and finds the strength to accept it, is she able to return home to Bybanks, having regained the peace and confidence within herself that her mother did love her, and that her disappearance and death had nothing to do with any perceived inadequacy in Sal.
A fourth archetype in Walk Two Moons is trees. Trees represent growth, they have roots, and they are an integral part of nature. Salamanca's middle name is Tree, indicating her closeness to and love of the natural world. Sal and her father also sense that the spirit of her mother and his wife lives on, because they can hear her in the "singing of the trees." Finally, Salamanca loves the trees at her home in Bybanks; they give her a feeling of rootedness and oneness with the natural world around her.