"Reconstructing past landscapes is not simple, and it will startle most people to learn that the Colorado River (or whatever was the major drainage of the region) used to run the other way..."

http://www.mauinews.com/page/blogs.detail/display/4468/Book-Review-289--Carving-Grand-Canyon.html

www.AcrossArizonaTours.com

The most asked question any Grand Canyon Tour guide is asked is, How was it (the Grand Canyon) formed? 

The book,  Carving Grand Canyon Restating the Obvious, by Wayne Ranney seem to me the best book on the subject I have read - and I have read a lot of books on the Grand Canyon!

Leonardo A. Gem
Across Arizona Tours