68 THE CLIMATIC FACTOR AS ILLUSTRATED IN ARID AMERICA. 



as did their neighbors 100 to 200 niiles to the north. They Ukewise constructed temples 

 oriented with the long walls pointing toward the place where the sun sets in May. Yet 

 they differed from the people of southern Ai-izona in that they were more skilled in the 

 arts of wall-building, defense, and agriculture. 



The Great Trinchera is of special interest because it appears to combine three types 

 of structures, rehgious, military, and agricultural. Possibly traces of houses may also be 

 visible, but we detected none. The hill is somewhat crescent-shaped, about 1,800 feet long 

 from point to point of the crest, and lying with the concave side facing almost due north 

 toward the distant river. Beginning at the base of the steep slope on the north side, 

 about 20 terraces rise one above another. Some are 5 feet high, and some 15; some 10 feet 

 wide, and others 20 or 30. Below these main terraces the ground slopes more gently than 

 above. Just where the slope changes, and in the center of the concavity of the hill, the 

 Hohokam built what seems to have been a temple or, better, a ceremonial platform, an 

 almost rectangular structure with a length of about 165 feet and a width, from north to 

 south, of 30 feet at one end and 40 at the other, a shape appropriate to a narrow terrace. 

 Rude walls of boulders piled up without cement surround the platform, and are pierced 

 by a door at the western end; while in the center of the north side a circular inclosurc, 

 12 feet in diameter, with a door to the south, appears to have been the holy place. From 

 all points of view the ceremonial platform stands out prominently, because it is the only 

 place from which all the stones have been carefully cleared. Its character is here empha- 

 sized, because it seems so plainly to be a rehgious or ceremonial structure, and as such is 

 strongly differentiated from all other structures on the hill. The portion of its walls 

 composed of stone was probably never more than 4 or 5 feet high, for, with the poor mate- 

 rials at their command, the Hohokam apparently could not build much higher without 

 mortar to bind the stones or tools to square them. The gentle slope below the temple is 

 broken into terraces like those on the steep slopes above, except that they are only 1 or 2 

 feet high and 20 to 50 feet wide in accordance with the angle of descent. We shall discuss 

 their purpose later. 



In early days the Hohokam of the Trinchera may perhaps have been as unwarlike as 

 those of Charco Yuma, but they certainly hved to learn the art of defense. The crest or 

 ridge of the hill is strongly fortified. Nine successive walls surround the main hilltop at 

 the western end. On the central part of the ridge, above the concavity in which lies the 

 temple, the Hohokam built a fort, breast-high, with walls 6 feet thick and mth a circular 

 bastion projecting from it on the exposed south side. Here and there on the terraces 

 little, low, circular inclosures, Uke those among the Rincon terraces, may have been of 

 service as outposts. Just how the Hohokam fought we do not know, but Mr. Harrison 

 found a collection of small cobble-stones 1.5 to 2 inches in diameter, just the right size to 

 throw. Evidently they were brought up the hill for some special purpose, which can 

 scarcely have been anything but defense. 



We now come to the question of the purpose of the terraces. Obviously they are not 

 for religious purposes, for the one religious structure is clearly differentiated from them. 

 They are equally differentiated from the mihtary portion of the structures on the hill. 

 None of them are protected by walls, and the lower ones (a foot or two high) would render 

 practically no defensive aid whatever. Ai-e they for habitation? According to local 

 tradition the Trinchera is a species of Tower of Babel. \Mien the flood, or possibly a flood, 

 overwhelmed the country, the Hohokam took refuge on the hills and made for themselves 

 dwelhng-places. There is no reason, however, to suppose that the terraces were ever 

 inhabited except temporarily. In the first place, pottery is too scarce to justify such a 

 supposition; in the second place, the shape is not adapted to habitation, for some of the 

 terraces are so narrow that there is scarcely room even for a tiny hut, and many terraces 

 taper to a point in a way wholly unsuited to houses. Finally, the whole aspect of the ter- 



