I bring to your notice my recent eBook entitled "Backpackers Fishing Guide to the Andes" which covers the best Andean regions from Venezuela to Tierra del Fuego.  My initial trout fishing experience was gleaned from a decade or more fishing the Tongariro River and the District Fisheries of New Zealand.  These NZ tactics worked just as well in South America and you really need only one "fly" for success, that being the Red Setter and its variants.  My book is listed at:
http://www.smashwords.com/books/view/150315
My profile is at http://www.smashwords.com/profile/view/allanotaylor