I first heard about Sepp Holzer from Jack Spirko at The Surival Podcast, in one of his many, many episodes on Permaculture. Sepp is a pretty fascinating farmer in Austria. He discovered many of the same driving principles of Permaculture in parallel to Bill Mollison in Australia, but completely independent of each other.
I received his book, Sepp Holzer's Permaculture for Christmas and went through reading it extensively before and immediately after we bought the property in Stony Point.
Sepp's original family farm (which is what he speaks about in the book) is called the Krameterhof and is 110 acres on the slopes of the Austrian Alps. The altitude range of the farm is 1100 to 1500 meters above sea level (just under 1 mile high at top top extents).
His farm is an incredible laboratory of techniques, especially with regards to terracing, water catchment and control, biodiversity, animal/plant systems, and growing things like citrus outside of their normal "acceptable" zones.
The book is a pretty easy read and for anyone who is dealing with any kind of elevation that wants to get into food forestry or permaculture, or even just some extreme gardening, this is definitely a book to add to your library.