Wanderlust World Wanderlust World In Sharon Creech's novel Walk Two Moons, Gram does not want to stop at Yellowstone National Park. The cross-country road trip with her granddaughter Sal follows a specific route dictated by family history—retracing Sal's mother's journey—not a sightseeing itinerary. Yellowstone lies far north of their actual path (Ohio → Idaho via the Midwest/Plains). Gram's urgency is emotional, not recreational: she's racing time to reach Lewiston, Idaho, by her mother's birthday. The novel's geography is precise; Yellowstone simply isn't on the way.