Who is telling the story in Walk Two Moons?

The primary narrator of Walk Two Moons is Salamanca Tree Hiddle, or Sal. She tells the story in two parts. One part is of her life in Euclid, Ohio, after she and her father moved there from Bybanks, Kentucky, before her mother left. The other part is of her road trip with her grandparents, to whom she tells the first story in a series of flashbacks, along with incidents from her life in Bybanks before her mother left.
Sal is what is called an unreliable narrator, which is one who does not tell all she knows. The events in the two stories have already happened in her past, but she waits until the end to reveal the truth to the reader. She drops hints along the way, which a second reading will make obvious. She is going with her grandparents to Idaho to reach her mother and bring her home by her mother’s birthday. While she says that her mother left her and her father to visit a cousin, she lets the reader assume that she might come back. It is not until the final chapters that Sal reveals her mother died in a bus accident. There are other mysteries along the way, including the whereabouts of Phoebe Winterbottom’s mother, whose disappearance in some ways mirrors that of Sal’s mother. All these clues tell what Sal knew all along.