NO. I ARCHITECTURE OF PUEBLO BONITO JUDD 5I 



Tree-ring dates merely suggest the period during which construc- 

 tion may have been under way. They cannot be taken at face value, 

 especially when few in number. Timbers were used and reused, as 

 Douglass (1935, 1939) observed after examining the material col- 

 lected by the National Geographic Society Beam Expeditions of 1923, 

 1928, and 1929. Chaco Canyon forests indubitably were reduced, 

 possibly destroyed, by builders of the major pueblos and while these 

 latter were under construction it is reasonable to believe that, suitable 

 trees being fewer and farther afield, easily accessible timbers were 

 being salvaged from one abandoned village and carried to the next, 

 as happened when Awatobi beams were transported to Hano and 

 Walpi. 



Decimation of the Chaco forests would have hastened formation 

 of a contemporary arroyo, and this in turn would have brought about 

 reduction in bordering farmlands. In arroyo formation, as Bryan 

 (1954, p. 12) pointed out, erosion progresses headward or upstream 

 and because there is progressive reduction in the number of rooms 

 and in the quantity of visible rubbish especially at Hungo Pavie, Una 

 Vida, Weje-gi, and Pueblo Pintado, it is my theory these east-lying 

 ruins, reflect an up-canyon shift of a reduced population. As their 

 fields failed, the village dwellers moved. And they moved just far 

 enough, a mile or two at a time, to keep beyond the annually advanc- 

 ing arroyo. Food has always been a strong incentive to migration ! 



With fewer data available, Kidder (1924, p. 55) doubted that 

 more than four or five major Chaco pueblos were inhabited simul- 

 taneously or that the population of the valley ever exceeded 6,000. On 

 the basis of our later observations, I would reduce those estimates 

 by half, to two great houses or three at most. I find no reason to 

 believe the Old Bonitians were involved in this theoretical upcanyon 

 population shift. They stayed behind, at least for a time, and 

 stubbornly tilled their ancestral acreage, however curtailed. Malnutri- 

 tion is evidenced in Old Bonitian skeletal remains recovered by the 

 National Geographic Society (Judd, 1954). It was the Late Bonitians 

 who moved and rebuilt and moved again. 



Stonework associated with datable timbers is a further index 

 to the age of a Chaco ruin. Florence Hawley (1938, p. 250) saw 10 

 distinct variations in Chaco Canyon masonry. At Pueblo Bonito I 

 recognized four principal varieties : the oldest, P. II or Old Bonitian ; 

 the other three. Late Bonitian. Twelve tree-ring dates recovered from 

 the older part of town extend from A.D. 828 to 935 ; 44 dates from 

 Late Bonitian houses range from 1011 to 1126. 



