The magic tree house takes Jack and his sister Annie to theGreat Plains where they learn about the life of the LakotaIndians.

 Mary Pope Osborne grew up in the military, and by the time she was fifteen had lived in Oklahoma, Austria, Florida and four different army posts in Virginia and North Carolina.
　　After graduating from the University of North Carolina at Chapel Hill in the early 1970's, Mary traveled all over Europe, and spent the first six weeks of her trip living in a cave on the island of Crete. She then joined up with a group of European young people and traveled in rickety vans through sixteen Asian countries, including Iraq, Iran, Afghanistan, Pakistan, India and Nepal.
　　She was a bartender, an acting teacher, a waitress, a travel agent, a window dresser, and a medical assistant -- all before becoming an author! Now she is the author of many highly acclaimed picture books, early chapter books, middle-grade biographies, and young adult novels.
　　In February 1993, Mary was elected the 27th president of the Author's Guild, the oldest, most established organization for writers in the United States