Natalie Pope Boyce and Mary Pope Osborne are sisters who grew up on army posts all over the world. They work together on Magic Tree House(R) Fact Tracker books to give readers information about the places, time periods, and animals that Jack and Annie discover in their Magic Tree House adventures. Natalie makes her home in the Berkshire Hills of Massachusetts. Mary is the author of all the Magic Tree House(R) fiction titles, as well as many more books for kids. For more information, visit the Magic Tree House(R) website at MagicTreeHouse.com!