A correct and detailed knowledge of the Indian trails leading through their country, and called by them warpaths, horse trails, and by the white traders "trading roads," forms an important part of Indian topography and history. Their general direction is determined by mountain ranges and gaps (passes), valleys, springs, water-courses, fordable places in rivers, etc. The early explorers of North American countries all followed these Indian trails: Narvaez, Hernando de Soto, Tristan de Luna, Juan del Pardo, Lederer and Lawson, because they were led along these tracks by their Indian guides. If we knew with accuracy the old Indian paths of the West, we would have little difficulty in rediscovering the routes traveled by Coronado's and Peñalossa's troops in New Mexico and in the great wastes of the Mississippi plains. In hilly lands these trails are, of course, easier to trace than in level portions of the country.