Campground Kids Set Books 6-12: Five books filled with page-turning action, adventure, and mystery that kids can't put down! The Campground kids is a book series you don't want your eight to twelve year old to miss out on. Kids across the country can't get enough of this mystery adventure series. Follow Isaiah, Sadie, and Ethan as they embark on their journey through some of the country's most beautiful National Parks, where they will encounter thrilling action, heart-pounding adventure, and captivating mystery at every turn.