MiNUELEFF] BOWLDER-MARKED SITES. 237 



storage reservoir. The surface of the mesa dips slightly southward, 

 aud the reservoir-like structure is placed at a point just above the head 

 of a large wash, where a considerable part of the water that falls upon 

 the surface of the mesa could be caught. It is possible that, commenc- 

 ing at the northern end of the settlement, a ditch extended completely 

 through it, terminating in the storage reservoir at the southern end, 

 and that this ditch was used to collect the surface water and was not 

 connected with the river. A method of irrigation similar to this is 

 jiracticed today by some of the Pueblo Indians, notably by the Hopi or 

 Tusayan and by the Zuni. In the bottom land immediately south of the 

 mesa, now occupied by several American families, there is a fine example 

 of an aboriginal ditch, described later. 



In the vicinity of the large ruin just above Limestone creek, previ- 

 ously described, the bowlder-marked sites are especially abundant. In 

 the immediate vicinity of that ruin there are ten or more of them, and 

 they ai'e abundant all along the edge of the mesa forming the upper 

 river terrace; in fact, they are found in every valley and on every 

 point of mesa overlooking a valley containing tillable land. 



It is probable that the bowlder-marked ruins are the sites of second- 

 ary and temporary structures, erected for convenience in working 

 fields near to or overlooked by them and distant from the home pueblo. 

 The character of the sites occupied by them aud the plan of the struc- 

 tures themselves supports this hypothesis. That they were connected 

 with the permanent stone villages is evident from their comparative 

 abundance about each of the larger ones, and that they were con- 

 structed in a less substantial manner than the home pueblo is shown 

 by the character of the remains. 



It seems quite likely that only the lower course or courses of the 

 walls of these dwellings were of bowlders, the sui)erstructure being 

 perhaps sometimes of earth (not adobe) but more probably often of 

 the type known as "jacal" — upright slabs of wood plastered with 

 mud. This method of construction was known to the ancient pueblo 

 peoples and is used today to a considerable extent by the Mexican 

 I)opulation of the southwest and to a less extent in some of the 

 pueblos. No traces of this construction were found in the bowlder- 

 marked sites, pei'hai)S because no excavation was carried on; but it is 

 evident that the rooms were not built of stone, and that not more than 

 a small percentage could have been built of rammed earth or grout, as 

 the latter, in disintegrating leaves well defined mounds and lines of 

 debris. It is improbable, moreover, that the structures were of brush 

 plastered with mud, such as the Navajo hogan, as this method of con- 

 struction is not well adapted to a rectangular ground plan, and if per- 

 sistently applied would soon modify snch a plan to a round or par- 

 tially rounded one. Temporary brush structures would not require 

 stone foundations, but structures composed of upright posts or slabs, 

 filled in with brush and plastereil with nmd, and designed to last more 



