The third is the Sierra Madre proper, which the Mexicans here call Sierra de Nacori, as the upper Bavispe River from its source makes a great detour toward the north around it, thereby partly separating it from the main chain.

Even this range does not really present any unsurmountable difficulties if the weather is fine; in bad weather, I admit, some parts of the trail we made would be all but impracticable.
Having reached the second range called the Sierra de Huehuerachi, near its northern terminus, and looking backward, we see the Sierra de Bacadehuachi lying farthest to the west.

On its eastern flank tower steep-tilted broken masses of conglomerate, and the frowning row of hog-backs just north and east of Nacori are only a continuation of that range.

But looking east from where we were we obtained the first close view of the main range of the Sierra Madre (Sierra de Nacori).

It rises bold and majestic on the opposite side of the valley, at the bottom of which runs the little river of Huehuerachi.
In this valley we camped for two days, being delayed by rains.