Backcountry Mexico: A Traveler's Guide and Phrase Book, Bob Burleson and David H. Riskind; 1986; While definitely not confined to Copper Canyon, this book is the best phrasebook/dictionary for ranchers or mechanics, or anyone who wants to know some esoteric Spanish.
Tarahumara of the Sierra Madre: Beer, Ecology, and the Social Organization, John G. Kennedy, 1978. Great book on the tesguinada; painfully researched I'm sure.
God's Middle Finger: Into the Lawless Heart of the Sierra Madre, Richard Grant, 2008. A guy looking for adventure and trouble, and finding it.
Tarahumara: Where Night is the Day of the Moon, Bernard Fontana, 1997. The subtitle of the book derives from the Tarahumar's belief that the soul works at night while the body sleeps and that during this "day of the moon" both the spirits of the dead and the souls of the living move about in their mysterious ways.
The Apache Diaries: A Father-son Journey, Goodwin & Goodwin, 2000. Apaches were in the Sierra Madre as late as the 1940's as documented by a kidnapping near Bacadehuachi. This book's investigation takes place primarily in the Sierra Las Espuelas, just west of Janos; but still the remote sierras.
Rain of Gold, Victor Villasenor, 1991. History of Batopilas. Review by Tina Rosa
Trail of Feathers: Searching for Phillip True, Robert Rivard, 2003. A murder investigaion in the Sierra Huichol.
In the Sierra Madre, Jeff Biggers, 2006. A tale of an American couple trying to fit in, and be accepted in a Tarahumaran village in the1980's.
Born to Run: A Hidden Tribe, Superathletes, and the Greatest Race the World Has Never Seen, Christopheer McDougall, 2009. On the New York Times bestseller book list for over 2 years. His book is a good read on several counts, and really made the running shoe industry take note- so they made those barefoot runners, instead. His book is interesting for (1)endurance, featuring the Tarahumara, (2) Caballo Blanco history, (3) The myth of running shoe, and that they basically created foot problems by trying to outdo nature's engineering of the foot.
The Life and Times of Pancho Villa, Freidrich Katz, 1998;. 100th Anniversary of the Mexican Revolution.