Unknown Mexico: Explorations in the Sierra Madre and Other Regions, 1890-1898 (Volume 1)

Originally published in 1902. From Preface - I first conceived the idea of an expedition to Mexico in 1887. I had heard of the wonderful cliff-dwellings in Southwest of the United States accessible in many cases only with aid of ladders. The Spaniards, when first discovering and conquering that district, are said to have come upon dwellings then still occupied. Might there not possibly be descendants of the people yet in existence in the northwestern part of Mexico so little explored? Thus from 1890 to 1898 I spent in field research abound the natives of northwestern Mexico. (Description by http-mart)