228 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I47 



sand eind day to the right of Station 50 clearly mark the bed of a 

 former watercourse, subsequently filled with debris of demolition 

 and it is possible the two walls beyond were erected to curb the 

 outward drift of that debris. The outermost wall is a little higher 

 and later than the other. But between and below the two is a nar- 

 row channel in which water once flowed, 5 feet below the present 

 valley floor. 



Running water had threatened the earlier wall from the outside 

 and, presumably to prevent undercutting, a willow mat, its com- 

 ponent rods horizontal, had been suspended against the lower stone- 

 work. But the water continued on its way, leaving clay-streaked 

 sand and gravel, until one of the local engineers brought it under 

 control by erecting a wattled wall opposite the mat. Rotted sticks, 

 apparently juniper, stood here at the time of our excavation, still 

 thickly coated on both sides with sun-dried mud. Three sandstone 

 blocks above the laminated silt may have been placed there to pro- 

 vide footing for the mason who built the second wall. Outside this 

 latter, filling what appears to be an old arroyo bed, is a succession 

 of sandy-clay, gravel, rocks, and water-washed village debris. 



Our two major trenches likewise revealed evidence that Pueblo 

 Bonito farmers undertook at times to harness midsummer floodwaters 

 and turn them to advantage. A channel on which man clearly exerted 

 a directing influence appears above Station 60 in the West Mound 

 trench (fig. 7). The bottom of it, gouged through occupational debris 

 filling an earlier and broader watercourse, Ues 6 or 7 feet below the 

 present level of the plain and is marked by a quantity of broken 

 rock purposely thrown there. Above the rock is a 2-foot-thick de- 

 posit of cross-bedded sand and, above the latter, a wide crescent of 

 laminated sandy clay. While this second layer was collecting, a 

 masonry wall was built along the south side of the channel. 



Shortly thereafter, as I read the record, this masonry wall toppled 

 outward and was lost under the continuing clay layer before a less 

 vigorous stream carved a shallower course outside the first and a 

 bit higher. To restrain this successor, or perhaps merely to check the 

 spread of household waste, a second and less stable wall was hur- 

 riedly erected (above Sta. 35). Beyond this second barrier, to the 

 right of Station 10, are the ill-defined limits of Bryan's post-Bonito 

 arroyo which, in Test Pit No. 3, measured 18 feet 3 inches deep — 

 well below the channels described above. 



What may be a continuation of this same walled waterway was 

 disclosed in the East Mound trench between Stations 20 and 35 



