The Secret of Bigfoot Valley — Gertrude Chandler Warner

The Aldens are spending their first week of summer at Camp Quest in Colorado. The children are excited to learn about fossil hunting and paleontology from renowned scientist Dr. Iris Perez. But strange events at the camp make them wonder if the legends of a bigfoot-like creature roaming the valley might be more fact than fiction. Can the Aldens help Dr. Iris figure out who -- or what -- is causing such a stir?