TWO TYPES OF SOUTHWESTERN CLIFF HOUSES. 
By J. WALTER KEWKES, 
Chief, Bureau of American Ethnology. 
[With 6 plates. ] 
There are probably few areas in the United States where there is 
a greater contrast in physical features, fauna, and flora than southern 
Arizona and New Mexico on the one hand and the northern regions 
of the same, including contiguous portions of the adjacent States, 
Colorado and Utah, on the other. Each area has characteristic 
geological and biological peculiarities; the rivers partake of the 
same differences. The lower Gila through much of its course 
flows through a great stoneless plain conspicuous by its cacti, its 
spine-bearing trees, mesquites, and palo verde. Its northern tribu- 
taries rise in high mountains in which this desert vegetation gives 
place to characteristic genera where sagebrush, cedars, pines, and 
spruces replace the Mexican chaparral. Both areas show evidence 
of great erosion, forming canyons (pl. 1) with many natural caves 
in their walls. 
The prehistoric human inhabitants of the two areas, as shown by 
the monuments left behind, also show marked peculiarities. Judged 
by his skill as a house builder, man reached a high development in 
both of these areas, but in both the mason’s craft deteriorated and 
the culture of the builders was materially changed or disappeared 
before the advent of the white man. Theoretically there is a relation 
of cause and effect between these differences of environment and cul- 
ture as indicated by architecture, and it is the object of this brief 
article to portray certain peculiarities in the character of cliff houses 
found in these geographical areas. 
So far as we can interpret the history of man in the temperate 
zone, the oldest evidences of his presence occur in caves. Even be- 
fore he built dwellings of stone he utilized caves as the best shelters 
his environment presented for that purpose. In the various steps 
in his advancement since that time he has lived in caverns, either 
natural or artificial, and often the construction of the buildings on 
these sites is noteworthy. What, in fact, would be more natural than 
that man in the early stages of his culture history should seek a cave 
or overhanging rock shelter for the protection of whatever food he 
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