On the other hand, last night I just finished reading "Flying the Mountains" by Fletcher Anderson, in which he seems to do a good job of passing on advice on the subject of the book's title. That advice also included warnings about low canyon flying, why you shouldn't do it, and if you must, why you should note where wires cross them prior to attempting such flights. Unfortunately the author died while flying low in a canyon and running into a wire crossing it. I would still recommend the book and its advice.