Ghost of Fossil Glen

Eleven-year-old Allie lives with her mother who has a job working in real estate. Allie has time to explore and go fossil hunting in the countryside around them. One day Allie hears a voice coming to help her, when she's stuck in a tight spot. Where does the voice come from? Could this be a ghost? What is the ghost trying to tell her about how she really died? Suspense and a great girl protagonist! Sequels are The Ghost and Mrs. Hobbs and The Ghost of Cutler Creek.