390 KEPOET UNITED STATES GEOLOGICAL SURVEY. 



That they both belonged to the community of cave-dwellers, and served 

 as their fortresses, council-chambers, and places of worship, would seem 

 to be natural and reasonable inferences. Being on the border of a low 

 mesa country that rises towards the north, the strong outside walls were 

 doubtless found necessary to prevent incursions from that direction, 

 while the little community by means of ladders would be free to pass 

 from dwelling to temple and fortress without danger of molestation. 



The original height of these structures must necessarily be a matter 

 of conjecture, and it is true that although there is every evidence of age, 

 both in the cave-dwellings and in the walled enclosures above, the lack 

 of great quantities of crumbling walls and debris, and the general bare- 

 ness of the ruins, give rise to the notion that they were but meagre 

 affairs. If we conclude, however, that the outer walls were constructed 

 for defence, and their thickness and form favor such a hypothesis, their 

 height would probably have been as great as fifteen or twenty feet, 

 while the inner walls, being equally heavy and well built, would be suf- 

 ficiently high to accommodate two or three stories. 



The manner of walling up the fronts of the cave dwellings, as here 

 given, was observed frequently on the Eio Mancos, where, in correspond- 

 ing cliffs of shaly sandstones, there are many well-preserved specimens. 

 A large group situated on this stream, about ten miles above its mouth, 

 was subsequently examined. The walls were in many places quite well 

 preserved and new-looking, while all about, high and low, were others 

 in all stages of decay. In one place in particular, a picturesque out- 

 standing promontory has been full of dwellings, literally honey-combed 

 by this earth- burrowing race, and as one from below views the ragged, 

 window-pierced crags (see Plate XXXII), he is unconsciously led to 

 wonder if they are not the ruins of some ancient castle, behind whose 

 mouldering walls are hidden the dread secrets of a long-forgotten people; 

 but a nearer approach quickly dispels such fancies, for the windows 

 prove to be only the door-ways to shallow and irregular apartments, 

 hardly sufficiently commodious for a race of pigmies. Neither the outer 

 openings nor the apertures that communicate between the caves are 

 large enough to allow a person of large stature to pass, and one is led 

 to suspect that these nests were not the dwellings proper of these people, 

 but occasional resorts for women and children, and that the somewhat 

 extensive ruins in the valley below were their ordinary dwelling-places. 

 On the brink of the promontory above stands the ruin of a tower, still 

 twelve feet high, and similar in most respects to those already described. 

 These round towers are very numerous in the valley of the Mancos. 

 From this point alone at least three others are in view, some on the 

 higher promontories, others quite low, within twenty or thirty feet of 

 the river-bed. I visited and measured seven along the lower fifteen 

 miles of the course of this stream. In dimensions they range from ten 

 to sixteen feet in diameter and from five to fifteen feet -in height, while 

 the walls are from one to two feet in thickness. They are in nearly every 

 case connected with other structures, mostly rectangular in form. At 

 the mouth of the Mancos, however, a double circle occurs, the smaller 

 one having been the tower proper. It is fifteen feet in diameter, and 

 from eight to ten in height. The larger circular wall is forty feet in 

 diameter and from two to four feet high, and is built tangent to the 

 smaller. This ruin is at the point where the Mancos reaches the allu- 

 vial bottom bordering the Eio San Juan, and about one mile above its 

 junction with that river. On the opposite or south side of the river are 

 traces of somewhat extensive ruins, but so indistinct that the character 

 of the original structures cannot be made out, and indeed no single 

 mile of the lower fitty of the Mancos is without such remains. 



