MARY POPE OSBORNE and NATALIE POPE BOYCE are sisters who grew up on army posts all over the world. They are working on more Magic Tree House Fact Tracker books to give Magic Tree House readers facts and information about places, time periods, and animals that Jack and Annie discover in the Magic Tree House adventures. Mary lives in Connecticut. Natalie makes her home nearby in the Berkshire Hills of Massachusetts. Mary is the author of all the Magic Tree House fiction titles as well as many more books for kids. SAL MURDOCCA has illustrated more than 200 children's trade and text books. He is also a librettist for children's opera, a video artist, an avid runner, hiker, and bicyclist, and a teacher of children's illustration at the Parsons School of Design. Sal lives and works in New York with his wife, Nancy.