More than ever since we entered the Sierra de Nacori, we noticed everywhere low stone walls, similar to those we had seen in the foot-hills, and evidently the remains of small cabins.  The deeper we penetrated into the mountains, the more common became these hut-walls, which stood about three feet high, and were possibly once surmounted by woodwork, or, perhaps, thatched roofs.  All the houses were small, generally only ten or twelve feet square, and they were found in clusters scattered over the summit or down the slopes of a hill.  On one summit we found only two ground plans in close proximity to each other.

The stones composing the walls were laid with some dexterity.  They were angular, but never showed any trace of dressing, except, perhaps, by fracture.  The interstices between the main stones were filled in with fragments to make the walls solid.  Neither here nor in any other stone walls that we saw were there any indications of any mud or other plaster coating on the stones.

On top of a knoll in the mountains south of Nacori, at an elevation of 4,800 feet, well preserved remains of this kind of dwelling were seen.  The house, consisting of but one room about ten feet square, was built of large blocks of lava.  The largest of these were eighteen inches long, and about half as thick, and as wide.  The walls measured about three feet in height and one foot and a half in thickness, and there was a sufficient amount of fallen stone debris near-by to admit of the walls having been once four or five feet high.  There were the traces of a doorway in the northwest corner of the building.  Numerous fragments of coarse pottery were scattered around, some gray and some red, but without any decoration, except a fine slip coating on the red fragments.

In the Sierra de Nacori, on the summit of a steep knoll, and at an elevation of about 6,500 feet, we found two huts of such laid-up walls.  The rough felsite blocks of which they were composed were surprisingly large, considering the diminutive size of the cabins.  We measured the largest block and found it to be two feet long, ten inches wide, and eight inches thick.  There were many others almost as large as this one.  But there was only one tier of stones left complete in place.  Although there were well-built trincheras in all the surrounding arroyos, there were no traces of either tools or pottery on that hill.

On the western slope of the Sierra de Nacori, on top of another knoll, and at an elevation of 6,400 feet, we found numerous rude ground plans, some of which showed rubble walls fifteen inches thick.  They formed groups of four or five apartments, each ten by twelve feet.  But on the north side of that summit there was a larger plan, nearly eighteen feet square; however, the outlines of the entire settlement were not distinct enough to enable us to trace its correct outlines.