What happens on the Wisconsin day in book Walk Two Moons?

On the Wisconsin day in the book Walk Two Moons, Sal and her mother take a detour on their journey to visit Sal's grandparents in Idaho. They stop in Wisconsin to visit the site of the car accident that killed Sal's mother's first husband, Gramps. Sal learns more about her mother's past and the challenges she has faced. The visit is a turning point in the book and helps Sal to understand her mother better and come to terms with her grief.