Walk Two Moons, by Sharon Creech, 1994

Salamanca Tree Hiddle sets out with her grandparents on a summer roadtrip to Lewiston, Idaho, to see her mother who went there a year ago and didn’t come back. Along the way Sal tells the story of her friend Phoebe Winterbottom, whose mother also left her family. Middle-grade realism; funny, tender, sad, hopeful; entirely worthwhile. Strongly recommended.