Some twenty-odd families of these live in caves during the wet season, and a few of them are permanent cave-dwellers.

I understand that the Pimas in Sonora utilise caves in the same way.
I made an excursion from the mine of Pinos Altos (elevation 7,100 feet) to Rio Moris, about ten miles west, where there are some burial caves; but they had already been much disturbed by treasure seekers, and I could secure only a couple of skulls.

An interesting feature of the landscape near Rio Moris is a row of large reddish pinnacles, which rise perpendicularly from the river-bed up along the hillside, and form a truly imposing spectacle.

An excited imagination may see in them so many giants suddenly petrified while walking up the mountain.

Around Pinos Altos and Jesus Maria the rock is of blue porphyry, quite hard in places, and speckled with little white patches.