A close friend of mine co-authored a book over 25 years ago that explains the Native American teaching of The Sacred Tree. With the recent popularity and success of the hit movie, Avatar, may who know the concept of the story of the Sacred Tree quickly made the connection with the Tree of Souls in the movie.
Please visit the following website, www.FWII.net (Four Worlds International Institute), for a more in depth description of the connection between The Sacred Tree and Avatar, along with a very nice excerpt from the book. Also you will find links on how to get a copy of the book, or you can go straight to Amazon.com and search for The Sacred Tree.
The book is also available for the Kindle.