BRACED-UP CLIFF, PUEBLO BONITO—JUDD 505 
here it was nondescript, with more blocks of dressed friable sandstone 
and fewer of laminate. Nevertheless the two varieties identify the 
terrace front as entirely a work of the Late Bonitians. 
During July and August 1933, Prof. John Y. Keur of the Depart- 
ment of Biology, Long Island University, undertook a study of various 
factors pertaining to the Braced-up Cliff and subsequently filed a 
report with the National Park Service (Keur, MS., 1983). Through 
the courtesy of Hurst R. Julian, at that time custodian of Chaco 
Canyon National Monument, I received a copy of that report and, in- 
asmuch as it supplements my own field notes in several important 
respects, I shall refer to it for pertinent details not visible at the time 
of our observations which entailed no excavations other than those 
already mentioned. The Southwestern Monuments Monthly Report 
from October 1933 to the final number, June 1941, contains additional 
data from Professor Keur and Park Service personnel.” 
Keur (MS., p. 4) dug pits at 50-foot intervals along the entire face 
of the terrace wall and found “near the base . . . several piles of 
mixed clay mortar.” From this I infer that the abutting adobe bank 
exposed in 1923 by our 5-foot-wide trench, although perhaps in reduced 
proportions and with occasional interruptions, continues the full length 
of the terrace. 
Keur’s trenches atop the platform revealed that the rubblework 
behind the frontal veneer did not extend to the Braced-up Cliff, as I 
had assumed, but ended at about half the distance. A trench at right 
angles to the cliff and midway, where underlying walls are lacking, 
shows (ibid., p. 5) the 32-foot-wide platform to consist of 16 feet of 
rubble (the “stone pier” of the manuscript) at the front, a packed- 
clay embankment near the base of the cliff, and a sand fill between 
clay and rubble. At the surface the embarkment measured 6 feet wide 
and the sand fill 10 feet, but at a depth of 7 feet the sand occupied only 
a 8-foot space while the clay bank had widened to 18 feet. This adobe 
embankment is doubtless the one indicated on our plan (fig. 2), only 
two sections of which were visible at the time the field sketch was made. 
Professor Keur regards the wedge-shaped sand fill between clay bank 
and stone pier as a sort of cushion intended to absorb any pressure re- 
sulting from the forward tilt of the Braced-up Cliff. 
It will seem incredible to the reader, as it does to me, that the Late 
Bonitians could have had such confidence in the cohesive properties of 
Chaco Canyon mud as to believe a manmade bank of it could prevent 
collapse of the great cliff towering 100 feet above. And yet I can 
imagine no other motive that would have caused them to construct 
with such prodigious labor a hand-packed mud embankment, 13 feet 
2 An earlier but cursory study of the braced cliff was made in 1916 by N. C. Nelson, 
of the American Museum of Natural History, and is briefed in Pepper (1920, pp. 389-390). 
