BRACED-UP CLIFF, PUEBLO BONITO—JUDD 509 
of Room 87 but did not dig deep enough to learn that the foundations 
of those old walls were built upon several large, irregular blocks of 
friable sandstone that rest upon clean sand 9 feet 10 inches below the 
Room 87 floor level. 
The external north wall of this original Old Bonitian settlement, 
and nearest the cliff, was banked high with blown sand when the 
Late Bonitians arrived and erected a row of abutting dwellings. One 
of these latter, Room 297, has its floor about 6 feet higher than that 
of the adjoining Old Bonitian room, 298. An exploratory trench 
lengthwise of Room 298 revealed large sandstone blocks in situ and 
surrounded by clean sand from 1 to 2 feet beneath the floor. Both 
the east and south foundations stand, in part, directly upon some of 
these blocks, and the fact that their upper surfaces, in several ob- 
served instances, slope down and toward the north clearly identifies 
them with an early fall from the cliff. Part of that same fall under- 
lies the northwest corner of Old Bonitian Room 296, 
Kiva N is a second-type Late Bonitian ceremonial chamber built 
against the south wall of Old Bonitian Room 83, previously men- 
tioned. In 1923 the north arc of Kiva N stood 9 feet 3 inches high; 
we estimated its original ceiling height at 9 feet 6. Four feet 7 inches 
below its floor or 14 feet below the estimated ceiling height at ground 
level, we came upon a massive section of friable sandstone, its upper 
cleavage plane slanting downward and to the northeast, as with those 
under Room 298. 
There can be no doubt that these several occurrences of native sand- 
stone deep under the floors of Old Bonitian houses represent collapse 
of a portion of the canyon wall long before the village site was 
permanently occupied. Spreading cliffward and fanwise from Kiva 
N, these buried fragments apparently broke away from approxi- 
mately the same section of cliff as did the next major fall, that which 
Mindeleff photographed in 1887 and which shows so clearly on Lind- 
bergh’s 1929 airview (pl. 1). 
It was this latter fall, occurring perhaps in the last half of the 
12th century after the Late Bonitians had left the valley, that crushed 
the west end of the broad terrace they had built with such great 
expectations and that hurled several massive chunks of sandstone 
dangerously close to their high north wall (pl. 5). The accumula- 
tion of broken masonry and windblown sand that had collected here 
before the hurtled blocks came to rest seems so scant (pl. 4, fig. 1) as 
to bring the incident almost within reach of recorded history in Chaco 
Canyon. Simpson (1850) had nothing to say of these farflung pieces 
when he entered Room 14b and carved his name on the wall plaster 
August 28, 1849, but he must have seen them. 
W. H. Jackson saw the great blocks in 1877, for he remarked that 
the rockfall of which they are a part occupied almost all the space 
