called "The Middle Finger of God"  Written by an 'adventure traveler' who's
idea was  to traverse the Sierra M
adre mountain region of NW mainland Mexico, he 'catches' the essence of the
culture there quite well, in that

  Here's a link to that book with a short reveiw.  Disclaimer..I know not
this author but I have traveled the 'main' road through that area and it
scared me!

http://search.barnesandnoble.com/Gods-Middle-Finger/Richard-Grant/e/9781416534402