The architecture of Pueblo Bonito : :: :: University of Virginia Library

This is a story of the growth and decline of a single prehistoric
village, Pueblo Bonito. It will have very little to say of other villages,
historic or prehistoric. It is a story primarily of houses and
house building. By adding to data previously published it seeks to
portray the manner in which a twofold Indian community rose to
preëminence and thereafter gradually fell apart and was lost.

Pueblo Bonito is the ruin of an Indian apartment house in Chaco
Canyon, northwestern New Mexico (fig. 1). Built and occupied
between A.D. 900 and 1100, it is one of 15 major ruins whose
preservation was intended by President Theodore Roosevelt when
he created the Chaco Canyon National Monument, March 11, 1907.
Of these, Pueblo Bonito is at once the largest, the oldest, and the most
famous (pl. 1).

Chaco Canyon, site of Pueblo Bonito, is a 15-mile-long section of
the Chaco River. Cliff House sandstone walls the canyon on either
side, but the river is a river in name only. Water flows through it
only during the annual rainy season when floods may race its full
length, a hundred miles from the Continental Divide to its confluence
with the Rio San Juan. Half a mile or more in width, the
canyon has never known a perennial stream, although it has sheltered
diverse primitive folk from the ancient Basket Makers to the nomadic
Navaho. Most advanced of these were the so-called Pueblo III
peoples, builders of Pueblo Bonito, 14 other major communities, and
numerous smaller settlements.

Over the centuries floodwaters have half filled Chaco Canyon
with alluvium washed in from higher ground and at least twice have
carved a watercourse, or arroyo, through that fill. Latest of these
arroyos, 30 feet deep and 100 to 300 feet wide as we measured it,
originated about 1850 and has since literally washed away at least

25 percent of the formerly arable land and thereby has largely destroyed
the most conspicuous plant on the valley floor, greasewood.
That 1850 arroyo is still in process of formation, but its predecessor,
about half as large, came into being while Pueblo Bonito was inhabited
and may have been a factor in compelling its abandonment.

Fig. 1.—The northwest quarter of New Mexico, showing location of Pueblo Bonito.

Since an arroyo promptly collects to itself all surface runoff,
vegetation is deprived of needed moisture and denudation follows.
Without grasses, trees, and shrubs to prevent erosion; and without
widespreading floodwaters to irrigate and replenish its fields, a
population dependent upon agriculture for a livelihood, as were the
Bonitians, could not long survive in a waterless valley.

We measured the elevation out in front of Pueblo Bonito at 6,250
feet, an elevation that indicates long winters and a relatively short
growing season. Despite this handicap the ancient peoples who dwelt
in Chaco Canyon obviously were content with their environment for
they stayed on generation after generation, tilling their gardens of
maize, beans, and pumpkins and building new homes as the need
arose. Lacking local records—the nearest dependable rainfall gage
was at the Crownpoint Indian Agency, 40 miles distant and 600 feet
higher—we have assumed a current annual precipitation of 10 inches
but this is clearly less than formerly. Chaco Canyon was greener
when Pueblo Bonito was inhabited and pine trees, cottonwoods, willows,
and rushes grew close at hand. Willows and a few cottonwoods
still survived as late as 1922 when Anderson prepared the map published
by Bryan (1954), but only rotted stumps, recumbent trunks
and two dead pines remained of the nearby forests that had furnished
timbers for the roofs of Pueblo Bonito (pl. 2, left, right).

Many of those timbers had grown under variable conditions, but
others had stood where subsurface water was so constant as to produce
annual growth rings of uniform thickness. Such uniformity
plus the willows, the rushes, and the cottonwoods all attest to a wetter
climate 800 or more years ago. We found no living spring but saw
small, thin reeds struggling for survival in sheltered coves where rainwater
seeps through the sandstone. In upper Rincon del Camino
one of our Navaho workmen had developed such a seepage zone into
a one-family water supply, the only one of its kind known to us.
Huntington (1914, p. 80) mentions a former spring half a mile from
"Hermoso," the south-cliff ruin known to National Park Service personnel
as Tsin Kletzin. The precise location of that spring remains
uncertain but it could be at the head of a shallow rincon just east of
Casa Rinconada where Navaho indicated a wet-weather seep.

We have postulated a current annual precipitation of 10 inches,
but just a little more would multiply native vegetation and thus
provide a check to floodwater erosion. One additional inch, according
to our geological advisers, would cause springs to flow again.
One additional inch per year, it is believed, would restore Chaco
Canyon to the haven it once was, bring back the grasslands where
deer and antelope browsed, and increase the harvest of seeds and
wild fruits available for human consumption.[1] The arroyo that has
made Chaco Canyon a wasteland since 1850, like the one that caused

comparable desolation 8 centuries before, eventually will fill with
alluvium and be forgotten but Pueblo Bonito remains a ruin, a magnificent
ruin (pl. 3).

DISCOVERY AND EXPLORATION

Pueblo Bonito was first described by Lt. James H. Simpson (1850,
p. 81) following a cursory inspection on the afternoon of August 28,
1849. Twenty-eight years later, in the spring of 1877, W. H. Jackson
of the Hayden Surveys camped 4 or 5 days at a muddy waterhole
west of Pueblo del Arroyo and during that brief period not
only mapped the valley but prepared ground plans and descriptions
of Pueblo Bonito and 10 other ruins—descriptions and plans
used by all who followed (Jackson, 1878). A decade after Jackson,
Victor Mindeleff of the Smithsonian Institution devoted 6 winter
weeks to surveying, mapping, and photographing those same ruins
for a report that never materialized (Mindeleff, 1891, p. 14; Powell,
1892, p. xxx).

The names by which the Chaco Canyon ruins are currently known
have been variously written, but herein, as previously, we adhere to
the spelling that was originally recorded by Simpson and Jackson
and which is that since accepted by the United States Geographic
Board, the Bureau of American Ethnology, and other recognized
authorities.

Merchants from Rio Grande settlements, militiamen on their several
missions, and U. S. Army engineers seeking a better route to
the Pacific visited Chaco Canyon before and after Simpson. Few of
these transients left any record of what they saw along the way, but
some among them did regrettable damage to the old ruins while
searching for souvenirs, and the finger of suspicion points to all.

Members of Colonel Washington's 1849 command have most frequently
been accused of this vandalism but Simpson himself exonerates
them. The troops camped for the night of August 26 about a mile
from Pueblo Pintado, at the head of Chaco Canyon, and 2 days later
left the valley at the Mesa Fachada (Fajada Butte), while Simpson
(1850, p. 78) and nine companions rode on to examine Una Vida
and other ruins, expecting to overtake the command by nightfall.

In 1877 old Hosta, one of Colonel Washington's 1849 guides, told
Jackson (1878, p. 435) that timbers were lacking at Pueblo Pintado
because soldiers "and other scouting parties" had used them for
campfires. Apparently a well-known trail passed this way from
Jemez and the Rio Grande settlements.

Military expeditions against the Navaho were recurrent in the
middle 19th century and more than one camped in Chaco Canyon.
On October 30, 1858, several members of Company E, Regiment of
Mounted Rifles, carved their names on the cliff back of Chettro
Kettle (Vivian, 1948, p. 16), and it is reasonable to believe that
these or other troopers were responsible at least for some of the
holes Jackson and Mindeleff saw in the north wall of Pueblo Bonito.
Years later, during military service at Fort Wingate, May 10, 1909,
to February 4, 1911, Privates Otto Wolford and John G. Bushman
of the 1st Troop, 3d Cavalry, successor to the Mounted Rifles,
carved their surnames at the top of the Pueblo Bonito stairway.

Mindeleff's 1887 photographs, earliest pictorial record of Pueblo
Bonito, provide visible evidence that seekers after treasure had preceded
him with pick and shovel. They had forced every sealed door in
search of open rooms and had breached the high north wall at 3- to
5-foot intervals throughout its full length (Mindeleff Neg. 3022).
"Relic hunting" was both a pastime and a vocation prior to passage of
the Antiquities Act of 1906.

The Wetherill brothers from their ranch near Mancos, Colo., had
discovered the famous cliff-dwellings of the Mesa Verde; had
gathered and sold several collections from these and other prehistoric
ruins. It was the hope of finding new ruins for exploitation that led
Richard Wetherill to Chaco Canyon in October, 1895, accompanied
by S. L. Palmer, his future father-in-law, and family. During the
next few weeks the two men amused themselves by digging for
curios, and both were successful. Palmer retained his share and
later lent it for display in the public library, Hutchinson, Kans.
(personal letter of June 8, 1921, to the National Geographic Society).

From Albuquerque after leaving Chaco Canyon, Wetherill wrote
so enthusiastically of collecting possibilities at Pueblo Bonito that
B. Talbot B. Hyde, of New York City, agreed to substitute a season
there for one previously planned for the Marsh Pass region, northeastern
Arizona (McNitt, 1957, pp. 109-113). This proved to be
the first of four expeditions, 1896-1899, financed by the Hyde brothers,
B. Talbot B. and Frederick E., Jr., and directed from New York
by Prof. F. W. Putnam, then curator of anthropology at the American
Museum of Natural History. Although the Hyde brothers had
previously purchased one or more archeological collections from
Wetherill, they stipulated that, this time, excavations should be pursued
under supervision of a recognized authority. The annual reports
of the Museum do not state that Professor Putnam visited the scene

of operations before 1899, but he was personally represented each
season by his assistant, George H. Pepper.

THE HYDE EXPEDITIONS

Outfitting at the Wetherill ranch the Hyde Expedition's freight
wagon, chuckbox at the rear, made open camp close under the north
wall of Pueblo Bonito early in the spring of 1896. There were no
tents; it was a relic collector's camp (Pepper, 1920, fig. 3).
Room 14b, where Lieutenant Simpson had carved his name August
28, 1849, was storeroom and kitchen; pipe for the camp stove was
raised against the outside wall. As Professor Putnam's representative,
Pepper supposedly was in charge of excavations but Wetherill
obviously wielded a greater influence. He was a rugged individualist
and not accustomed to taking orders, especially from a younger man;
he had recommended the site and previous experience there told him
where to dig; he spoke Navaho and Navaho Indians were employed
as workmen; his teams did the freighting from Mancos to Chaco
Canyon and back again.

In his biography of Richard Wetherill, Frank McNitt (1957)
extols the undeniable capabilities of his subject while belittling
Pepper for his lack of western training, for being less experienced
than Wetherill in digging relics, and for the meticulousness of his
excavation notes. Between the lines, however, one gains the impression
that Putnam's instructions to Pepper did not always prevail;
that the random selection of rooms for excavation was sometimes
made with a view to their possible contents; that the sums annually
available for expenses were never adequate; and that Wetherill
never drew a living wage for his efforts. This last fact prompted
various additional undertakings on his part, including another collecting
campaign to Grand Gulch during the winter of 1896-97.

At the end of the second season at Pueblo Bonito, Wetherill had
a one-room trading post built against the outer north wall, connecting
with Room 14b (Pepper, 1920, fig. 4; McNitt, 1957, p. 173); the
following year, 1898, a larger store with residence adjoining was
erected near the southwest corner of the ruin, and the Hyde Exploring
Expeditions, with Wetherill as manager, were in the Indian trading
business on a large scale (Holsinger, MS., p. 70; McNitt, 1957,
p. 191). Travelers on various missions came and went; a boarding
house for employees at the southeast corner of Pueblo del Arroyo
was retitled "the hotel"; excess guests were quartered in tents or in
patched-up rooms in Pueblo Bonito. Among others, Rooms 122-124

were revamped and reroofed for occupancy. These same rooms were
later utilized by the School of American Research (Hewett, 1921,
p. 12), and they were still habitable when we repaired them for
laboratory use in 1925 (pl. 4, upper).

During the summers of 1896-1899 the Hyde Expeditions cleared
190 rooms and kivas in Pueblo Bonito, numbered serially as excavated.
In lieu of the final report that never was written, Pepper's rough
field notes went to press hurriedly in the fall of 1920, some 10 years
after he had left the American Museum of Natural History. As
published, those notes do scant justice either to Pepper, the Hyde
brothers, or to the American Museum, but they are indispensable to
full understanding and appreciation of Pueblo Bonito. Since they
pertain largely to portions of the ruin we did not explore, I have
drawn upon them repeatedly in this study of local architecture.

As explained in the introduction to the 1920 publication, its accompanying
ground plan was prepared by B.T.B. Hyde from Pepper's
original memoranda and photographs, a preliminary survey
made in 1900 or 1901 by Prof. R. E. Dodge, and a 1916 sketch by
N. C. Nelson. That such a composite might include several inaccuracies
was anticipated by Mr. Nelson (ibid., p. 387) and those we
discovered have been corrected on our own plan (herein, fig. 2)
and so reported in text and tables.

Pepper states (1920, p. 339) that only "minor excavations" were
made in Rooms 116-190 because "nothing of special interest" was
developed in them. A different explanation was offered by Jack
Martin, a one-time Hyde Expedition freighter and my teamster during
the Society's 1920 reconnaissance of the Chaco country: Outside
rooms were cleared by Wetherill to or near floor level in anticipation
of resumption of Hyde Expedition excavations. But these latter had
been brought to an end by Government pressure in 1901, the year a
local post office was authorized under the name "Putnam" and the
year Hyde Expedition headquarters were moved to Thoreau, on the
Santa Fe Railroad.

It is unfortunate that no data relative to this particular sequence,
116-190, were recorded at the time of excavation, for all are of Late
Bonitian construction and many overlie earlier walls. Of Rooms 1115,
on the other hand, 59 are Old Bonitian structures from which the
4 Hyde Expeditions recovered the wealth of household utensils,
objects of personal adornment, and ceremonial paraphernalia that
ever since have been held up as illustrative of the cultural heights attained
by the inhabitants of Pueblo Bonito. Those treasures, however,

are mostly from Old Bonito. With few exceptions they represent the
culture of the Old Bonitians, a P. II people, and not that of their
P. III coresidents.

If an aura of commercialism still hangs over the work of the Hyde
brothers at Pueblo Bonito it is more a reflection of the period than of
association with Richard Wetherill, whose undeniable interest in
archeology is not easily divorced from his activity as a collector.
Relic hunting was legitimate and unrestricted at the time of the
Hyde Expeditions, 1896-1899; anyone could dig for relics and keep
what was found. This wide recognition of "finder's keeper" was
evident even at Pueblo Bonito where the Hydes repeatedly had to
purchase specimens their own employees had pilfered (Pepper, 1905,
p. 190; 1920, p. 330; McNitt, 1957, p. 167). One eastern museum
curator, irresistibly tempted by reports of fabulous discoveries, even
ravaged a couple rooms after the Hydes had withdrawn at the end of
their first season (Pepper, 1920, p. 210). Transient guests at expedition
headquarters amused themselves by searching for souvenirs in
the nearby ruin. Not until 1906 was a Federal law passed to prohibit
unauthorized digging on the public domain and then largely to check
the exploitation of Pueblo Bonito and other Chaco Canyon ruins.

THE PUEBLO BONITO EXPEDITIONS

Twenty years after the Hyde Expeditions came to an end and prior
to the announced publication of Pepper's field notes, the National
Geographic Society authorized the explorations reported herein and
previously. Originally planned for 5 years but subsequently extended
two more, the Pueblo Bonito Expeditions were expected to discover
what factors had brought about the extraordinary Chaco Canyon
civilization in what had come to be an unwatered, impoverished, and
relatively uninhabited region. The Society's Committee on Research
desired to identify the builders of Pueblo Bonito, if possible; to discover
where they came from and where they went. The agricultural
possibilities of the valley in prehistoric times, its then sources of water
and fuel, and the location and extent of the ancient forests that had
furnished timbers for the roofs of Pueblo Bonito and neighboring
communities likewise were subjects for inquiry (Judd, 1922a, p. 117).
Not until Pepper's volume appeared in the early summer of 1921 was
it known that comparable studies had originally been planned for the
Hyde Expeditions (Wissler, in Pepper, 1920, p. 1).

On the ground plan herein (fig. 2) rooms numbered 1-190 are
those opened by the Hyde Expeditions. To correlate our studies with

Fig.2__Ground plan of Pueblo Bonito with cross sections
A-A′, B-B′, and C-C′. (From the original survey of Oscar B.
Walsh, 1926)

theirs, rooms excavated for the National Geographic Society likewise
were numbered, beginning with 200, but our kivas were lettered.
When we had exhausted the first kiva alphabet we began a second,
each letter prefixed by the numeral 2. In both text and tables, room
numbers followed by the letters B, C, or D indicate, respectively, the
second, third, and fourth stories.

Of those bearing our numbers, Rooms 210, 227, 295, 299, 300 and
Kivas Y and Z were cleared by unknown persons between 1900 and
1920. We numbered but did not excavate Rooms 205-208, 297, and
301-303; Kivas O, P, S, and 2-C were merely tested for pertinent
information. It was my personal hope that these 12 and all those left
unnumbered might be reserved for examination some years hence.

Except as noted hereinafter, we made no inquiry in rooms excavated
by the Hyde Expeditions, 1-190. During our third season,
however, the better to control surface drainage in the older section
north of Kiva 16, we removed or leveled quantities of excavation
debris left by our predecessors (pl. 5, lower). It was this effort,
perhaps, that prompted Hewett (1921, p. 17; 1930, p. 302; 1936,
p. 32), to state that I had unknowingly excavated rooms cleared and
refilled by the Hyde Expeditions.

After Pepper's 1920 volume became available we utilized his
recorded field notes as fully as possible. But there were additional
data that seemed essential to the history of Pueblo Bonito.

Extramural stratigraphy.—Two conspicuous refuse mounds, the
principal village dump, lie immediately south of the great ruin. Refuse
heaps normally reflect the cultural changes of any community and
potsherds provide a convenient means for measuring such changes
in a prehistoric settlement. Since discards at the bottom are naturally
older than those above, one of our first undertakings in the spring of
1921 was a 5-foot-wide trench through a previously undisturbed
section of the West Mound, larger of the two. A stratigraphic
column, 3 feet square, at the end of that trench reached clean sand
at a depth of 19 feet 5 inches (pl. 6, left). From 23 unequal layers
floored by ash, variously colored sand, or otherwise, we collected 2,119
potsherds (U.S.N.M. No. 334180).

That sherd collection disclosed a puzzling mixture of pre-Pueblo
and later pottery types, top to bottom. There were 93 fragments of
Plain-banded Culinary ware and 778 fragments or 36.7 percent, of
Corrugated-coil. Early and late varieties of Black-on-white were
present in all 23 layers; Black-on-red, in more than half. Straight-line
Hachure occurred in every stratum except the two lowest, V and W.

Brown-with-polished-black-interior occurred in all but five strata:
B, S, U, V, and W. A single Mesa Verde sherd was recovered in
Layer E, the bottom of it 3 feet 7 inches below the surface. ProtoMesa
Verde fragments appeared above the 9½ foot level but not
below. This 20-foot intermixture of early and late pottery came as
such a complete surprise I questioned our findings and cut another
column.

Next, I undertook to examine surrounding soils by means of 7 pits,
4 to 12 feet deep, dug at various distances and in various directions
from Pueblo Bonito. None exhibited more than stratified sand, windblown
and water-washed, with intervening silt layers, occasional
lenses of gravel, bits of charcoal, and chance potsherds. A humus
layer that might have identified a once-cultivated field was nowhere
seen. And, despite a secret hope, none of my seven pits revealed any
trace of the long-sought Bonitian burial ground.

We began our second season with a third column through West
Mound rubbish and followed it with an East Mound test. Two years
later we tried both mounds again. Then, in 1925, after my own
efforts had failed, I invited Frank H. H. Roberts, Jr., to join my
field staff and take charge of the local problem in stratigraphy. The
invitation was extended upon recommendation of Dr. A. V. Kidder,
a long-time friend and confidant, and chiefly in recognition of
Roberts's convincing analysis of BM.III-P.I pottery from the PagosaPiedra
region, southwestern Colorado. At Pueblo Bonito Roberts was
assisted by the late Monroe Amsden after the latter, under special
permit from the Department of the Interior, had concluded a study
of 16 small-house ruins in and south of Chaco Canyon (U.S.N.M.
Nos. 329803-45).

As graduate students in anthropology Amsden, at Washington,
D. C., and Roberts, in Cambridge, Mass., had assisted during the
winter of 1924-25 in analyzing the Pueblo Bonito potsherds I had
previously collected. Failing health compelled Amsden to relinquish
his part in this joint undertaking thus leaving to Roberts principal
responsibility for our study of Pueblo Bonito ceramics, a study that
had made scant progress prior to unexpected discoveries early in 1925.

Intramural stratigraphy.—During our fourth season, 1924, we had
cleared the West Court to its last recognizable occupation level (pl.
7, upper) and, in so doing, had discovered that village waste and
blown sand were piled up 6 feet 7 inches—almost ceiling high—against
the outer east wall of Old Bonitian Rooms 329-330. Consequently
one of our first tasks of the 1925 season was to seek explanation for

that accumulation. We made a number of tests close along the west
side of the Court and then, boldly, extended our 1921 West Mound
trench to the ruin and northward to Kiva Q.

That extended trench (pl. 6, right), 5 feet wide and 12 feet deep,
solved our 4-year-old puzzle, the mixture of early and late village
refuse. At a depth of 10 feet 2 inches we came upon the floor of a
Great Kiva, over 50 feet in diameter, built inside a huge excavation
expressly dug in a vast accumulation of household rubbish and later
completely razed. Rubbish from that excavation, nearly 2000 tons of
it, may well have started the West Mound—the mound we had profiled
4 times, 1921-1924. Sandstone spalls and chunks of dried mortar
from the razed kiva added to the displaced rubbish. So, too, did
quantities of current floor sweepings.

Just outside the south limit of that razed kiva was a previously
undisturbed section of the original trash pile. Into that remnant
Amsden and Roberts, to whom I had entrusted our entire stratigraphic
study, sank two yard-square test pits the first 13 feet deep and the
second, 12 (fig. 7). As in any other dump, discards at the bottom were
older than those above and the sequence in which they occurred,
bottom to top, provided the information on which Roberts and
Amsden based our knowledge of local ceramics.

Much has been written about the prehistoric pottery of Chaco
Canyon. Beginning with Kidder (1924), archeologists have extolled
the exceptional whiteness of its surface slip, the variety and the perfection
of its hachured designs, the blackness of its paint. More than
one has puzzled over the association there of Early Pueblo and Late
Pueblo vessel shapes and ornamentation, of mineral paint and vegetal
paint—enigmas not solved until Amsden and Roberts cut their two
12-foot-deep tests into sub-court debris at Pueblo Bonito. From
Test 1 they recovered 3,593 potsherds; from Test 2, 2,934.

The 2,934 sherds from Test 2 (U.S.N.M. No. 334175), to limit
this presentation, occurred as follows:

													Percent
Strata	A	B	C	D	E	F	G	H	I	J	K
Black-on-white	97	277	225	130	137	266	132	53	64	2	6	1,389	47
Plain gray	30	173	127	102	117	212	104	48	64	27	8	1,012	35
Broad band	10	55	40	42	50	72	29	7	10	1		316	11
Narrow band						17	5			2		24	1
Nail-cut band	1	4		2	1				1			9	0.3
Waved band			1									1
Corrugated-coil	23	47	43	1								114	3.5
Black-on-red	1	9	9	5	4	14	15	4	5			66	2
Pol. black inter	1	2										3	0.1

Roberts and Amsden separated their 1,389 Black-on-white sherds
into 19 lots including "miscellaneous" (37.5 percent) and those with
no trace of paint (23.9 percent). Of the remainder, design elements
familiar to all students of Pueblo history appeared at various levels
and in the following proportions:

													Percent
Strata	A	B	C	D	E	F	G	H	I	J	K
Straight hachure	4	31	8									43	3.1
Squiggled hachure	6	2	7	3	6	16	7	3	5			55	3.3
Ticked lines	4	10	16	5	15	18	7	6	4			85	6.2
Waved lines		4	5	4	3	7	8	4	1			36	2.6
Stepped triangles	5	16	17	25	9	20	12	4	9			117	8.5
Dotted triangles	6	3	13	15	9	9	9	4	4			72	5.2
Volutes	1	6	7	3	3	13	5	3	3			44	3.2
Checkerboard		1	1		1		3	1				7	0.5
Opposed dentates	1	2	2		1	4	2	1	2			15	1.1
Chaco-San Juan	11	15	5									31	2.3
Mesa Verde		1										1	0.1

To process the vast quantity of potsherds we had previously
recovered from excavated rooms and trenches, Amsden and Roberts
established a workshop in reconditioned Rooms 122-124 at the southwest
corner of the ruin (pl. 4, upper). Here they sorted, counted at
least twice, and classified an estimated 2,000,000 potsherds. After
eliminating all recognizable duplicates there remained 203,188 fragments
for tabulation, and these, coupled with data from West Court
Tests 1 and 2, provide a framework for the history of pottery making
at Pueblo Bonito. At the end of our studies all unwanted sherds were
reburied, many of them in the West Mound cut made for our dumpcars
and track (pl. 5, lower).

In reporting upon the material culture of Pueblo Bonito I paraphrased
some of Roberts's field notes in listing the diagnostic features
by which he and Amsden cataloged their Test 1 and Test 2 potsherds,
and I summarized Miss Anna O. Shepard's identifications of local
pigments and tempering agents (Judd, 1954, pp. 177-183; see, also,
Shepard, 1939, p. 280). Nevertheless, for the present volume it seems
desirable to augment my earlier review by more liberal citations from
the memoranda Roberts recorded in 1925.

The preponderant pottery from Tests 1 and 2, a total of 25
vertical feet, was an assemblage that seemed to span the years from
Pueblo I to Pueblo II in the Pecos classification (Kidder, 1927) or
from earth-walled pit-houses to those of single-coursed masonry.
Hence the term "Transitional" Roberts and Amsden coined to bridge
the time between. Nearly half of this assemblage was a gray-paste

ware, primarily sherd-tempered and coated with an off-color white slip,
polished before painting. The paint was of mineral origin and black
or sometimes rusty-brown owing to inexpert firing or to insufficient
iron.

Slips varied from thick to thin and were sometimes carelessly
applied; both paint and slip sometimes showed a tendency to chip or
peel—variations I attribute to the misfortunes of production rather
than to intent. Rims were direct, tapered, and painted black; pitchers
were full-bodied and round-bottomed; ladles were of the half-gourd
form until later experimentation turned toward the bowl-and-handle
type. Bowl sherds with polished black interior, although found deep
in the two principal refuse mounds south of the village, occurred in
the uppermost layers only of Test 2. Cook pots were of the smoothbodied,
banded-neck variety—broad to narrow bands, plain or indented
—until followed by all-over Corrugated-coil.

Passing vogues in vessel form and painted decoration are evidenced
from bottom to top in these and other stratified deposits. Squiggled
hachure began early and so did stepped triangles, waved lines, and
free-standing figures. There were transient preferences for designs
composed of broad solid lines, for hachured figures with solid tips,
and others balanced by opposing elements. After this old rubbish pile
had accumulated to a depth of 8 feet, Straight-line Hachure was
introduced, first with widely spaced composing lines within heavy
frames and then with closer bars and lighter framing.

Contemporaneously with Straight-line Hachure and Corrugatedcoil,
or shortly thereafter, our so-called "Chaco-San Juan" type made
its unexpected appearance—a black-on-white variety with a lightgray,
stone-polished slip, tempered chiefly with pulverized potsherds
and ornamented with Mesa Verde-like designs in organic paint. In
thickness and rim treatment, Chaco-San Juan bowls exhibit a compromise
between Mesa Verde and Chaco practices. Instead of being
tapered and painted black in the Chaco tradition, rims are usually
rounded and variously ticked; bowl exteriors are often carelessly
bordered or slap-dashed across the bottom with a full slip-mop.

In Pueblo Bonito stratigraphy this Chaco-San Juan variety appears
earlier and much more abundantly than Mesa Verde Black-on-white,
but, although Roberts and Amsden separated the two while studying
Chaco Canyon pottery in 1925, I admit an inability at this late date to
distinguish one from the other except for individual pieces. Both are
of wide distribution among the mesas and valleys of southeastern
Utah and southwestern Colorado; both are perhaps best described by

Kidder's still useful, but rarely used, term "proto-Mesa Verde"
(Kidder, 1924, p. 67). And I have since come to think of both as
more or less synonymous with McElmo Black-on-white.

Classic Mesa Verde with its thick-walled bowls and flattened rims,
its superb polish, and precisely executed designs, reached Chaco
Canyon just as the high local culture was on the way out. Other late
imports such as Houck, Kayenta, and Chaves Pass polychrome,
Mimbres and Tularosa Coil (Judd, 1921, p. 110), and a few fragments
of Navaho or Apache conical-base pots were also present. A
black-on-red variety, or perhaps two varieties since Amsden and
Roberts divided the lot by color, puzzled us at the time because
sherds from early rubbish included fragments with hachured designs
and ticked rims.

What we called "Mesa Verde," including a few fragments of
undeniable Classic, comprised only 0.4 percent of the 208,188 sherds
Roberts and Amsden tabulated at Pueblo Bonito, while our ChacoSan
Juan group made up 6.6 percent of the total. Of 1,830 potsherds
recovered during excavation of Kiva A, 22.6 percent were Chaco-San
Juan and 10.4 percent Mesa Verde, but, among those from a limited
subfloor test in the same chamber, percentages were 8.1 and 2.7,
respectively. Four Chaco-San Juan sherds among 694 from a subfloor
test pit show that Old Bonitian Room 307 was built later than
others of its kind.

While presenting these and other data gathered within the pueblo
and without, I desire once again to stress the significant fact that
no fragment of Straight-line Hachure, most widely cited element on
Chaco Canyon pottery, was recovered below Layer C, 4 feet 2 inches
from the surface in 12-foot-deep Test 2. This is equally true for
Corrugated-coil Culinary and our Chaco-San Juan variety. Below
Layer C every painted sherd was decorated with a black mineral paint
and most of them were exclusively sherd-tempered. Sherd temper
and mineral paint unite this pottery from the lower 8 feet of Test 2,
the pottery of Old Bonito. Associated culinary vessels were rock- or
sand-tempered, with smooth bodies and banded necks.

There are those who will disagree; but to me it seems obvious
that a typological break occurs at this 8-foot level; that makers of
a different pottery complex came to dwell at Pueblo Bonito after Old
Bonitian household waste had accumulated to a depth of 8 feet or
more. For myself only, the gray-paste, mineral-paint, black-on-white
pottery from that lower 8 feet, the "Transitional," remains a single
ware indistinguishable in composition and ornamentation from the

slaty-gray or grayish-white, sherd-tempered, mineral-paint pottery
known throughout the San Juan country as "Mancos Black-on-white."

Although widely reported and often illustrated, Mancos Black-onwhite
was first described by Martin (1936, pp. 90-94) from Lowry
Ruin, northwest of Mesa Verde National Park, southwestern
Colorado. Subsequent investigations broadened his original description:

. . . a Chaco-like were found in southeastern Utah and southwestern Colorado.
It manifests the same general treatment, appearance, and elements of design as
early Chaco pottery. These design elements are: squiggly, diagonal hatch;
checker-boards with solid or hatched squares; pendent or opposed triangles, solid
or hatched; terraces, or stepped elements; panels of oblique or vertical lines
bordered by ticked lines, opposed triangles, or other solid elements; quartered
patterns; cross or diamond hatch polka dots; solid elements bordered by parallel
lines; plain stripes; ticked and double ticked lines; scrolls; allover patterns . . .
of oblique parallel lines . . . ; chevrons; and combinations of two or more of
these elements (Martin, 1938, p. 268).

Writing from Santa Fe 10 years later, Reed (1958, p. 81) added
to Martin's definition: "Mancos Black-on-white is characterized by
tapered direct rims, unpainted or painted (sometimes smoothly
rounded or nearly squared, sometimes ticked); moderately thin vessel
walls . . . largely unslipped surfaces . . . typically dark bluish gray
. . . but also very often light gray; iron paint; sherd temper"—an
addition that appears to combine Roberts's definitions of the Transitional
and Chaco-San Juan varieties noted at Pueblo Bonito. Of a
collection then in hand Reed wrote (ibid., p. 95): "Fully half the
sample lot of Pueblo III sherds from stratigraphic work in Chaco
Canyon deposited in the Laboratory of Anthropology by Roberts is
solid-style Mancos."

Presumably that sample lot came from one of the two tests Roberts
and Amsden cut through 12 feet of household sweepings under the
West Court at Pueblo Bonito. Because Pueblo Bonito is customarily
thought of as a Pueblo III ruin exclusively, Reed erred in assuming
that every sherd in the sample was dated by the P. III fragments
present. Actually, as I have attempted to emphasize repeatedly,
Roberts and Amsden collected P. III sherds, including those of
Pueblo Bonito's famed cylindrical vases, from the upper 4 feet only.
Any accompanying Transitional, or P. II, fragments merely prove
continuing production of the latter following arrival of P. III
potters.

If the "solid-style Mancos" recognized by Reed in half the sample
lot supplied by Roberts is identical with Mancos Black-on-white, a

diagnostic of Pueblo II civilization all the way across southwestern
Colorado and southeastern Utah, then it was brought to Chaco Canyon
by the immigrating Old Bonitians, a P. II people. There are those
who will disagree, but to me the black-on-white pottery of Old
Bonito has contributed to the Chaco-like resemblances reported from
beyond the San Juan River fully as much as have the three varieties of
Straight-line Hachure and other P. III pottery types of the Late
Bonitians.

Since 1925 a numerous nomenclature has been advanced to identify
every visible difference in Southwestern pottery, including that from
Chaco Canyon. Personally, I find this multiplicity of terms more
confusing than helpful. Those used at Pueblo Bonito by Roberts and
Amsden still seem adequate but other students may prefer other
designations. Each minor variation or error in manufacture does not,
in my opinion, constitute a new variety. Differences in paste composition,
surface finish, or density of pigment may be seen even on opposite
sides of the same vessel, witness the 232 black-on-white
specimens illustrated in "The Material Culture of Pueblo Bonito"
(Judd, 1954).

In 1921, 1922, and again in 1925 our season's plans were discussed
in the field with a chosen company of friends and colleagues skilled in
Southwestern geology, physiology, Indian agriculture, and related
subjects. Only the inadequacies of an archeological camp 95 miles
from a corner grocery limited the number of our guests. Nevertheless,
from impromptu discussions about the evening campfire came
knowledge of Chaco Canyon's past history, its one-time forests, its
prehistoric arroyo, and other factors reflected in the following pages.
A welcome addition to our 1925 company was W. H. Jackson, then
82, whose 1877 survey first focused public attention upon Pueblo
Bonito and its barren surroundings.

We examined Navaho fields to observe the methods practiced by
local Indian farmers. We analyzed soils, flood waters, and well
waters to ascertain their mineral content. Test Pit No. 3, 9 feet
2 inches deep, was situated midway between camp and the ruin (pl.
7, upper). Soil samples taken at 10-inch intervals in that pit showed
an excess of sodium salts (black alkali), top to bottom, that would
have rendered those soils impervious to water. Without water to wet
the soil there would be no crop; without ample harvests a people
dependent upon farming for a livelihood, as the Bonitians were,
could not long survive as a compact, walled-in community.

The ancient forests of Chaco Canyon and the dating of Pueblo

Bonito.—Thousands of pine logs had gone into the roofing of Pueblo
Bonito. We wanted to learn the source of those logs; we hoped to
discover when they were felled. Toward this second objective, the
tree-ring method developed by Dr. A. E. Douglass, then director of
Steward Observatory, University of Arizona, as a means of measuring
the effect of sunspots upon climate and tree growth, seemed
most promising for our purpose. Using materials furnished by the
American Museum of Natural History he had previously correlated
Pueblo Bonito with Aztec Ruin and learned that sections of beams
then in hand showed Pueblo Bonito to be older than Aztec.

In 1922 Dr. Douglass graciously agreed to aid the Society's search,
and I promptly sent him all the wood samples we had recovered from
Pueblo Bonito the year before. But I am reasonably sure that, as he
studied these specimens, his thoughts were focused more upon sunspot
influences than upon the age of Pueblo Bonito. It was 7 years until,
and largely in consequence of the National Geographic Society's
special Beam Expeditions of 1923, 1928, and 1929, he recognized the
feasibility of a tree-ring calendar reaching backward into unrecorded
history (Douglass, 1929, 1935).

At the beginning of our search for the age of Pueblo Bonito
Dr. Douglass, who had been working with the giant redwoods of
California, assured me that any timber less than 6 inches in diameter
was scarcely worth saving. But it was not long thereafter before he
was eagerly scanning every scrap we salvaged—splintered door lintels,
beam borings, and charcoal paraffined and wrapped with twine. I
mention these facts because his early results, published in the National
Geographic Magazine for December 1929, and in the first number
of this series (Douglass, 1935), made the dating of Pueblo Bonito
seem such a simple achievement that few, even among his own students,
realize the discouragements initially encountered and overcome.
Now his method is commonly accepted as a trustworthy guide in
Southwestern archeology, and many minds have lengthened his
original list of dated tree rings (Douglass, 1935).

The 97 specimens from Pueblo Bonito sent to Douglass in 1922
and following, together with the place of origin and his determinations,
are presented hereinafter, but individually they told us more
than their age. They told us that many had been cut in winter or
late autumn; that many had grown where moisture was surprisingly
constant for a region now virtually waterless. Because the individual
specimens were generally from straight-grained timbers, clean,
smooth, and unscarred by transportation it was obvious the trees they

represented had grown at no great distance; had been felled and peeled
while green, and carried by manpower to the building site. But the
forests from which they came are no longer in existence. A dozen
pines, living and dead, stood at the head of Chaco Canyon at the time
of the Society's 1920 reconnaissance; four others, all dead and three
of them fallen, were later seen in Wirito's Rincon, about 2 miles
southeast of Pueblo Bonito (Douglass, 1935, p. 46).

Elderly Navaho told us of pine trees and stumps formerly present
in Mockingbird Canyon and elsewhere. Unknown persons, according
to one informant, had cut the pines on neighboring mesas and their
stumps had been used for fuel by Mexican sheepherders. Always the
sheepherders were to blame! Old Wello, with a steel ax issued at
Fort Defiance before the turn of the century, felled two small pines
on the rimrock at the head of Wirito's Rincon. He wanted them for
repairs to his cabin, built by cattlemen at the north end of Peñasco
Blanco mesa about 1880 and abandoned shortly thereafter. And,
knowing I was from Washington, the old man took particular pains
to assure me he had cut only two of the three pines then standing. A
lone survivor, 5 or 6 inches in diameter, had won anchorage in shallow
soil upon the south cliff overlooking our camp and stood there defiantly
until some needy individual cut it for firewood during the winter of
1926-27 (Douglass, 1935, p. 40).

These scattered remnants, the dead logs in Wirito's rincon, the
stumps in Mockingbird canyon and beyond, the decayed trunk from
the West Court at Pueblo Bonito, the lone survivor on the south cliff,
and the cluster of pines 15 miles to the east are all that remained in
1924 of forests which once crowned the mesas overlooking Chaco
Canyon and extended down through the rincons and out upon the
valley floor.

Whatever their extent or limitations, those ancient forests had
produced thousands of choice timbers, large and small, for Pueblo
Bonito and its neighbors. These timbers grew under diverse conditions
as may be seen from the 97 specimens we recovered. In some
of these, annual growth rings are so uniform as to indicate a nearly
constant water supply year after year; in others, rings are thin,
starved, and stunted. These differences could reflect either a variable
climate or merely unlike growing conditions.

That rainfall was once more plentiful in Chaco Canyon is suggested
not only by growth rings in trees but also by the quantities of reeds
and willows utilized in construction of Pueblo Bonito. Willows and
reeds require moisture, and geologists tell us that ponds or swampy

places capable of nourishing reeds and willows could have been
brought about, prior to erosion of the present arroyo, by only a slight
increase in annual precipitation. Perhaps echoing recollections heard
in boyhood, several of our elderly Navaho neighbors emphatically
insisted that Chaco Canyon was greener "before white men came,"
that grass was then belly-high to a horse, and water could be had anywhere
with a little digging.

These geological opinions and these Navaho recollections lend
credence to the theory of climatic change in the Southwest, as advocated
by Huntington (1914) and others. Paucity of rainfall has long
been considered a principal cause of arroyo formation in the Southwest,
and Douglass (1935, p. 49), with his tree rings before him,
sees a succession of droughts down through the years. There was a
short one about A.D. 920; another, around 980; still another, more
severe and more widespread, between 1090 and 1101. Of our 59
datable timbers from Pueblo Bonito only two were cut during that
decade; only six were felled during the 40-year period of subnormal
rainfall, 1005-1044.

"In the 500-year history of Oraibi even the small droughts were
accompanied by reduced building" (Douglass, 1932, p. 312).
Throughout the long advance of Pueblo civilization, house construction
always declined in times of reduced rainfall (Mindeleff, 1891).
Timbers from old Hopi villages and trees from Arizona forests show
that periods of below-average precipitation recurred irregularly during
the 10th, 11th, and 12th centuries but Pueblo Bonito had been
deserted 100 years or more when the Great Drought of 1276-1299
caused far-reaching devastation throughout the Plateau Province and,
presumably, hastened abandonment of the famous cliff-dwellings of
Mesa Verde National Park.

The prehistoric arroyo.—In 1924 and 1925 Dr. Kirk Bryan, a
geologist with the U. S. Geological Survey and an acknowledged
authority on groundwater resources of the Southwest, undertook in
our behalf a study of sedimentation and erosion in Chaco Canyon.
He examined minutely the banks of the present arroyo, of post-1850
origin, and learned much previously unsuspected of Chaco Canyon
history. He discovered dead campfires and bits of broken pottery
20 feet and more below the surface; he noted that relics of Pueblo III
peoples, the builders of Pueblo Bonito and its kind, occurred in the
upper 4 feet only and those of earlier peoples below that level.

Bryan learned that the main Chaco Canyon fill had been built up
over the centuries by intermittent floodwaters that shifted from place

to place, back and forth, stopped and flowed on, as they deposited
their load of sandy silt and thus annually freshened areas for cultivation.
This silting-up process was a slow one since floodwaters drop
only part of their burden in passing and are lightly turned aside by
a tuft of grass, a clump of greasewood, or a temporary barrier of
wind-borne sand.

Some of that sandy silt was laid down so uniformly by gently flowing
floods as to leave floor-smooth surfaces varying in width from a
few feet to several hundred. Where W. H. Jackson in 1877 noted the
foundations of small P. III ruin "5 or 6 feet below the general level
of the valley" (Jackson, 1878, p. 443), bedded silt previously deposited
extends out on either side, northward to surround Pueblo del
Arroyo and southward across the width of the canyon (Bryan, 1954,
pl. 6, upper). We came upon similar layers beneath the floors of
Pueblo Bonito and farther east, under the abandoned foundations of
a proposed Late Bonitian addition.

In their normal course, wandering floodwaters may erode channels
of greater or less permanence. One such, close under the south walls
of Pueblo Bonito, had persisted year after year despite determined
efforts to dam it with village debris. It had attained a depth of 10
feet and its course had been turned repeatedly toward mid-valley
before the Bonitians won the struggle. It was a forerunner of Chaco
Canyon's destructive 12th-century arroyo which became Kirk
Bryan's primary interest in 1924 and 1925.

Bryan first came upon this prehistoric arroyo near the southeast
corner of Pueblo del Arroyo where Jackson in 1877 had discovered an
earlier exposure 14 feet deep (Bryan, 1954, p. 32). From that
point of discovery Bryan traced the ancient channel up and down
canyon for several miles. Because sand and silt had gradually filled it
to overflowing and continued thereafter to accumulate until its banks
were buried under an additional 4 or 5 feet of alluvium, Bryan soon
came to refer to that prehistoric arroyo as "the buried channel." And
because potsherds found on the bottom of it could be correlated with
the final decades of Pueblo Bonito, he often employed a second
descriptive term, "the post-Bonito channel" (Bryan, 1925, 1926, 1941,
1954).

In his published papers, and especially that of 1954, Bryan reviews
the history of this buried watercourse and discusses its probable
influence upon the occupants of Pueblo Bonito. Where Douglass
blames the builders for decimating the ancient Chaco forests and
thus hastening arroyo formation, Bryan blames the arroyo. It was his

opinion that, by lowering the water table, the buried channel was
chiefly responsible for the denudation of Chaco Canyon and destruction
of Bonitian farmlands.

Chaco Canyon pioneers.—In his study of local geology, Bryan
observed artifacts of the Bonitians and their contemporaries in the
upper 4 feet of the valley fill. Below that level every potsherd was
a product of Early Pueblo (P. I) or Basket Maker peoples. These
were the pioneers of Chaco Canyon! They lived in slab-walled, earthcovered
houses or in single-room pits dug deep into the valley floor,
the roofs supported by four posts.

One such pit-dwelling, on the south side of the canyon opposite
Pueblo Bonito, was partially excavated in 1920 (U.S.N.M. Nos.
315892-901); two years later caving of the arroyo bank a mile to the
east exposed a second pithouse, its floor 12 feet 2 inches below the
present surface (Judd, 1923, p. 136; 1924b, p. 404). After its
abandonment 6 feet of floodwater silt and sand was deposited above
roof level. Charred timbers from this buried home have been dated
A.D. 720 and 777 (Douglass, 1935, p. 44, fn. 1; Smiley, 1951, p. 19);
pottery and other artifacts (U.S.N.M. Nos. 324801-844) are typically
P. I, as Roberts (1938) stated in correcting an earlier misinterpretation.

A third pit-dwelling, its floor at a depth of 13½ feet, had been
half washed away before we discovered it. What remained hung
in the west bank of a narrow gully 9 miles east of Pueblo Bonito
(Judd, 1927, p. 168). On the opposite bank and 13 feet higher, a
small P. III ruin was partially cleared by Frank Roberts that same
summer, 1926, as he tested a nearby BM. III village site for the
Pueblo Bonito Expeditions (Judd, ibid., p. 165). A year later
Roberts completed excavation of this village for the Bureau of American
Ethnology and has so ably reported its distinctive features
(Roberts, 1928, 1929) there is no need herein to review the results
of his 1926 testing. Shabik'eshchee is the only Late Basket Maker
village known in Chaco Canyon, but there may be others.

The surviving portion of that gully bank pit-dwelling was described
by Roberts as "Arroyo House." Under an equally appropriate name,
"Half House," the same remnant was rediscovered and redescribed
by Adams (1951) who postulates two "separate and distinct" occupation
levels, lists 11 types among its potsherds, and cites Deric
O'Bryan's tree-ring dates of A.D. 700-740 for charcoal fragments in
the initial fill. Both Adams and Roberts classify this ancient dwelling
as Basket Maker III but the same evidence could as easily read

Pueblo I. In any case this deep-lying pit-house and the one we cleared
8 miles down valley were both occupied in the 8th century, A.D.

The broken floors of two more BM. III or P. I pit-dwellings were
revealed by our 1925 exploratory trench 11 feet 9 inches below the
West Court surface or approximately 6 feet below the present valley
surface south of Pueblo Bonito (fig. 7). In both instances sandstone
slabs on end, packed between and held upright with mud, marked
floor limit. Another early house remnant, including a 16-inch-high
section of stone-topped adobe wall, was bared on a silt surface 6 feet
3 inches below floor level in Room 241. The builders of Pueblo Bonito
probably were unaware of these and like remains deep beneath their
foundations.

THE RUINS OF PUEBLO BONITO

Based on our tabulation (Appendix A), Pueblo Bonito included
an estimated 651 rooms of which 152 were Old Bonitian and the
remainder, Late Bonitian. If all were inhabited simultaneously, which
is unlikely, and if an average family of five occupied three rooms, a
local population of 1,090 is indicated. But these are only approximations;
the real totals lie beyond our reach. Thus, for our present purpose,
Pueblo Bonito at the height of its fame, A.D. 1000-1100 or
thereabout, was a compact pile of 600 or more rooms from one to
four stories high, the home of possibly 1,000 individuals (pl. 8).

Pueblo Bonito was the creation of two distinct peoples, each selfsufficient
and each with its own cultural heritage. The original settlers
had been in residence a long, long while before the second group
arrived to take up joint occupancy of the village and proceed, forthwith,
to dominate its varied activities. Lacking the names by which
they knew each other, I have called the first group "the Old Bonitians";
the second group "the Late Bonitians" because they were,
in fact, late comers to Pueblo Bonito. Their common home, more
than 3 acres in ground area, was strictly utilitarian; shelter and subsistence
were of primary concern to both peoples. Neither built
monumental religious structures; neither sought to commemorate
the accomplishments of previous leaders.

In 1920 during the Society's reconnaissance of the Chaco area the
four Zuñi accompanying me returned from their first tour of Pueblo
Bonito and voiced their joint conclusion: "White men built those
walls; Indians could not." From Simpson's time forward the masonry
of Pueblo Bonito and its neighbors has astonished all visitors to
Chaco Canyon, irrespective of nationality.

Pueblo Bonito was in ruin when the National Geographic Society
began its explorations in the spring of 1921. The pine and fir timbers
"in excellent condition" seen by Simpson, Jackson, and Mindeleff
had been pulled out or sawed off; many individual door and
ventilator lintels had been dislodged or severed with steel axes. Local
Navaho charge this vandalism to "sheep herders" and "soldiers" and
perhaps with some justification but part of the blame lies elsewhere.
In his letter of June 8, 1921, to the National Geographic Society,
S. L. Palmer observed that wood from the old ruin was
used for fuel when he and his family accompanied Richard Wetherill
to Pueblo Bonito in October, 1895. Later, and before passage of the
Antiquities Act of June 8, 1906, Wetherill erected his several homestead
buildings and, in part at least, roofed them with ancient timbers
from Pueblo Bonito.

In 1877, with particular reference to Pueblo Bonito, Jackson
(1878, p. 441) wrote "many of the vigas, which are in excellent
preservation, still retain their places and protect a number of rooms
on the first floor." If not before, then shortly after Jackson's visit
every room with ceiling intact had been discovered and appropriated
by transient whites. The Hyde Expeditions utilized Room 14b and
those nearby; Wetherill later repaired for his own use Rooms 25, 105,
119, and others adjacent to his residence. Room 295, which we
cleared, is not readily accessible but it had been entered, perhaps from
Room 88. Tin cans and broken glass strewed the floor; a large hole
had been broken through the southwest wall and nails driven into
its door lintel. Sometime later all beams and ceiling poles had been
severed with steel ax or saw.

Pueblo Bonito was an empty shell when the National Geographic
Society began its explorations and it was the desire of the Society's
Committee on Research to preserve it as such, a monument to its
prehistoric builders. Toward this end we employed each season one
or more crews to repair previous damage as our investigations advanced
(pl. 9, left). In this repair work, partly listed in Appendix C,
we used only sandstone and mud—materials the Bonitians had used—
and, where needed, ax-hewn timbers trucked in from Smith's Lake,
50 miles to the south. The old beam and ceiling-pole fragments we
introduced during these wall repairs do not, of course, date the
original masonry.

The cement capping about Kivas C and D (pl. 45, lower), erroneously
attributed to the National Geographic Society in Park Service
literature of the period, was actually an experiment in drainage

control undertaken by the National Park Service itself in April and
May 1925 (letter to the director from Superintendent Pinkley,
Dec. 24, 1925). Further experimentation was pursued during the
summers of 1927 and 1928 under personal supervision of Martin
L. Jackson, at that time custodian of Montezuma Castle National
Monument, Camp Verde, Ariz. The Pueblo Bonito Expeditions
used no cement in their repair work.

As stated heretofore, I regard Pueblo Bonito as the creation of
two distinct peoples, the Old Bonitians and the Late Bonitians. They
vanished 800 years ago, but we may know them from their distinctive
architecture and the products of lesser industries (Judd, 1954).
Presumably both peoples were born under the well-known Pueblo
matrilineal system wherein the mother ruled the family and owned
the house. Men might help with the heavier work of construction—
quarrying stone, fetching and placing beams—but the women presumably
laid the walls and plastered them, as women still did when
Bourke (1884) and Mindeleff (1891) visited the Hopi and Zuñi
villages. At that time family quarters might consist of one room or
half a dozen. Building and plastering normally were late winter or
springtime tasks when melting snow filled nearby pools. Living
rooms were to the fore, storerooms at the rear or underneath.

Old Bonito was a Pueblo II community in every respect, built of
wall-width slabs of sandstone, each slab spalled around the edge
"much as a flint blade would be chipped"—to quote Morris's (1939,
p. 34) singularly apt description—and held one upon another by mud
mortar pressed into place with bare fingers (pl. 10, 1). Wherever
seen about the pueblo, house walls of this character identify the
builders as Old Bonitians.

The exterior rear wall of Old Bonito, double-thick at floor level,
had no door. Outside and upon 4 to 6 feet of sand wind-piled
against that rear wall, Late Bonitian architects erected a single row
of rooms embodying the first of their three principal varieties of
stonework. To compensate for the slanting exterior of Old Bonito
the abutting new masonry was backed with building waste or, where
space invited, it rose to form a succession of wedge-shaped storerooms,
as from 101 east to Room 298 (fig. 4). One gains the impression
this addition was erected primarily to conceal the haphazard
irregularity of the old wall.

In sharp contrast to that of Old Bonito, Late Bonitian masonry
consists of a rubblework core faced on both sides by a veneer of
neatly fitted sandstone blocks. Foundations are of roughly broken,

Plate 2

Dead pine, Wirito's Rincon, southeast of Pueblo Bonito.

(Photograph by Karl Ruppert, 1922.)

Recumbent pine logs, head of Wirito's Rincon, 2 miles
southeast of Pueblo Bonito.

(Photograph by Neil M. Judd, 1926.)

Plate 3.—Pueblo Bonito from the north cliff in 1920.

The east and west refuse mounds, with Nelson's 1916 stratigraphic tests showing, lie beyond the ruin. At left, Wetherill's 1897 store.

(Photograph by Charles Martin, 1920.)

Plate 4

Upper: Rooms 122-124, rebuilt by Richard Wetherill, were repaired by the Pueblo Bonito
Expedition for laboratory use.

(Photograph by O. C. Havens, 1925.)

Lower: An apparently unfinished wall in the southwest corner, East Court, overlay older
structures. Above, the exterior of Rooms 150-152 with ancient repairs.

(Photograph by Neil M. Judd, 1923.)

Plate 5

Upper: East Court excavations near close of 1922 season. Room 190 and fragment of cross-court
wall lie below paired dump cars; Pit No. 3 lies between ruin and camp, right margin.

(Photograph by Neil M. Judd, 1922.)

Lower: The West Court at beginning of the 1924 season; Kiva 16, left foreground; 1898
Wetherill house and store, upper right.

(Photograph by O. C. Havens, 1924.)

unshaped stones as a rule and may be offset several inches or recessed
by a like amount—evidence that the foundation was prepared
in advance and not always to the satisfaction of the masons who followed.
Upper-story walls, invariably thinner than those next below,
suggest upward construction after each successive floor was completed,
hence the presence or absence of so-called floor offsets and
their variability.

Although it is possible to see others, I recognize three principal
varieties of Late Bonitian masonry. The first of these, that of the
outside row mentioned above, combines blocks of soft, friable sandstone
dressed on the exposed surface with hammerstones or abraders
and interlaced with quarter-inch-thick tablets of harder, thin-bedded,
laminate sandstone (pl. 10, 2).

In the second variety of Late Bonitian masonry (my third type
at Pueblo Bonito), tablets of laminate sandstone ½ to 1 inch thick
were neatly arranged between blocks of friable sandstone 3 to 4 inches
thick (pl. 10, 3). At its best this second variety, its individual blocks
hand-smoothed and of uniform size, had an artistic quality none will
deny (pl. 27, right) Later the denser laminate stone was often substituted.

As their experience with Chaco Canyon sandstone advanced, Late
Bonitian architects increasingly favored the harder, laminate variety
until, in their third and final variation (the last of my four Pueblo
Bonito types), friable sandstone was practically eliminated (pl. 10, 4).
This final variation—the climax of all Bonitian masonry—is largely
restricted to the southeastern portion of the pueblo where, with no
loss of time, it was substituted for an intended addition whose abandoned
foundations extend 500 feet eastward (fig. 11).

Soft, friable Cliff House sandstone is available all along the
base of the north canyon wall wherever portions have broken away
and the harder, thin-bedded variety was formerly to be had on top,
back some distance from the brink. Because it breaks readily into
blocks that fit snugly with a minimum of mortar, this thin-bedded
variety became an early favorite of Late Bonitian builders and they
eventually exhausted the supply. I recall a pile of it, a one-man
load, left on the cliff edge midway between Pueblo Bonito and
Chettro Kettle and individual pieces scattered through the sand below.

Together, these four distinct kinds of masonry—one, Old Bonitian;
three, Late Bonitian—frame Pueblo Bonito as we know it today.
Late Bonitian masonry has won for Pueblo Bonito a reputation that
will endure for all time, but, in our general admiration, the cruder

stonework of the Old Bonitians is commonly overlooked. This latter
never changed; it remained the same from beginning to end—wallthick
slabs of spalled sandstone bedded in mud mortar and stometimes
studded with thin stone chips (pl. 11, right). Late Bonitian builders
erected second-story, and possibly third-story, partitions upon pine
beams bridging lower rooms at ceiling level but the Old Bonitians
never attempted this architectural feat so far as we know. Nor did
they introduce longitudinal stringers within a wall to equalize vertical
pressure.

In an effort to illustrate the relationship of these four kinds of
masonry, one to another, I marked out three separate cross sections
with the expectation of showing thereon all pertinent data from our
excavations. That the results (figs. 13-15) are less than anticipated
may be attributed to my unwillingness to risk visible structures in
order to bare others deeply buried. Figure 2 is of the ground floor
only; our data pertaining to individual rooms, upper and lower, are
condensed in Appendices A and B.

Old Bonitian and Late Bonitian homes had their similarities and
their dissimilarities. They differed in size, construction, and built-in
fittings. Of 43 Old Bonitian ground floor rooms for which data
are available, ceiling height averages 7 feet and floor area 120¾
square feet. Of 86 first-story Late Bonitian rooms (12 of secondtype
construction; 40, third-type; 34, fourth-type) ceiling height
averages 8 feet 5½ inches; floor area averages a fraction over 142
square feet and increases with each advance in masonry.

Ceilings.—Late Bonitian ceilings consisted of carefully selected
pine and fir beams and poles supporting successive layers of dressed
willows or pine boards, cedar bark, and adobe mud (pl. 12, upper).
Old Bonitian ceilings, on the other hand, were casual assemblages of
whatever materials lay near at hand: cottonwood, pine, pinyon, or
juniper logs covered with brush, reeds or grass, cornstalks, and other
chance gleanings (pl. 12, lower). Old Bonitian beam ends are characteristically
conical, the beaverlike gnawing of a stone ax unmistakable.

Late Bonitian beams, ceiling poles, and door lintels were of selected
straight-grained timbers, felled and peeled while green, and
the knots rubbed off. Ceiling poles normally were seated in the wall
masonry a couple inches but beams continued all the way through,
their ends cut to a previously incised line, smoothed by a sandstone
abrader and mudded over when the wall was plastered (pls. 13,
right; 52, right). A flint chip marked the limiting line and Late

Bonitian ax-work, to the amazement of many observers, equaled
that of a course, cross-cut steel saw (pl. 61, left). Stone axes from
Pueblo Bonito are notoriously crude and few in number, but the Late
Bonitians in some unaccountable manner were capable of trimming
and placing their larger beams with an exactness that suggests prior
measurement. Old Bonitian timbers frequently extended several feet
through a wall, as in Rooms 302 and 304, but Late Bonitian timbers
that did so, as in 227, are few in number and may indicate no more
than an unwillingness to shorten a salvaged log.

In Old Bonitian homes pine ceiling poles of uniform diameter and
spit juniper shakes probably evidence Late Bonitian reconstruction.
Hatchways were present in both Old Bonitian and Late Bonitian
ceilings, usually in the southeast corner.

Doors.—There is no door in the rear wall of Old Bonito and only
7, so far as we know, that once opened courtward from its groundfloor
living-rooms. Those in Rooms 28 and 83 were provided with
masonry steps to court level; the other five may be improvisations,
cut through the old walls after later rooms were built in front of 306,
307, 323, 325, and 326.

Wherever we found them, Old Bonitian doors were more or less
oval, approximately 22 inches in maximum width by 30 inches high,
with mud-padded jambs rounding off top and bottom, and a sill height
varying from 12 inches in Room 32 to 4 feet 9 inches at the north
end of Room 325 (pl. 14, left). Late Bonitian doors, in contrast,
are neatly regular with low sills and lintel poles of uniform diameter
lashed together above the jambs and often extending to, or part
way to, the walls on either side (pl. 14, right).

Many Late Bonitian doors shown partly blocked on our ground
plan (fig. 2) probably were not blocked at all but had been left open
for convenient passage during construction and were filled in later to
the desired sill height. Hence the appearance of partial blocking seen
in some of our illustrations. Among others, doorways in Rooms
246B, 247, and 291 are silled with dressed pine boards; those in 227
and 228B, with inverted Old Bonitian tabular metates instead of the
customary sandstone slab.

Storeroom doors were fitted from the outside with slabs leaning
against secondary lintels and jambs (pl. 13, left). All secondary
lintels we noted at Pueblo Bonito were filled in above with masonry;
none stood free for support of a cold-weather blanket, as described
by Bourke (1884, p. 134) and Mindeleff (1891, p. 182) in Hopi and
Zuñi homes of the past century.

Both the diagonal door, leading cornerwise from one room to another,
and the Tau-shaped door appear to be Late Bonitian introductions.
Of the former (pl. 15, left) we know of only seven or
eight, all in houses of fourth-type masonry; of Tau-shaped doors,
32 in number, all but two are found in Late Bonitian walls.

Architecturally, the diagonal doorway seems such an admirable
idea one would expect to find it in general use and from an early date.
But quite the contrary. Relying upon memory rather than a fresh
search of the literature, I recall only one example from another Chaco
ruin and none at all among ancient cliff-dwellings. W. H. Jackson
(1878, p. 436) described a diagonal door in a second-story wall at
the northwest corner of Pueblo Pintado, but, surprisingly, he reported
none at Pueblo Bonito although those connecting Rooms 173B and
228B, 180B and 242B, must have been visible to him in 1877 as they
were to Mindeleff 10 years later. The feature appears occasionally
in P. III ruins north of Chaco Canyon but only occasionally.

The T- or Tau-shaped door is an enigma. It is widely distributed
throughout the Southwest both in historic and prehistoric villages,
but no one to my knowledge has yet advanced a convincing explanation
of its form or purpose. I have seen T-doors in prehistoric ruins
as far west as Navaho Mountain but in none earlier than P. III.
At Pueblo Bonito T-shaped doors were peculiar to the Late Bonitians
since only two examples are known in Old Bonitian houses, and
one of these, that connecting Rooms 321 and 323, is so conspicuously
framed in third-type stonework as to evidence Late Bonitian alterations.
Without regard to masonry, 23 of our 32 T-shaped doors occur
in ground floor rooms, eight in those of the second story, and one in
the third story, between Rooms 174C and 175C. This latter and
those in the west walls of 226 and 227 were interior doorways; all
others faced upon one of the courts. Largest of all, 7 feet 4 inches
high and a foot above the floor, opened through the east wall of
Room 334 upon the roof of Kiva T (pl. 16, left).

Two miniature T-shaped recesses, both empty, occur in the south
wall of Old Bonitian Room 326B (pl. 11, left) which stands 8 feet
4 inches above its floor level with no trace of ceiling poles. Rarely
does an Old Bonitian house boast a third story.

Ventilators are seen in rooms of all four masonry types. Altogether
we have record of 183 of which 28 appear in 10 Old Bonitian rooms;
11 in six houses of second-type construction; 33 in 19 third-type structures,
and the remainder in 53 fourth-type rooms six of which are in
the third story. Ventilators vary in their dimensions and in height

above the floor; those of the second-story are usually larger than firststory
ventilators. Of our total, 122, or 67 percent, had been wholly or
partially closed with masonry, usually to leave a shallow inside recess.

Since ventilators presumably were intended to provide cross ventilation,
the blocking of them, whether partial or complete, would
seem to indicate a desire for simple physical comfort. Winters are
cold in Chaco Canyon and reduced or closed ventilators would lessen
winter drafts. I place no faith in theories that the blocking was a
defensive measure. Nine ventilators in the west walls of two Old
Bonitian storerooms, 320 and 217B, were sealed with stonework when
the Late Bonitians erected their 2-story row of second-type rooms
adjoining.

Storage shelves and clothes racks.—Single poles, 2 to 3 inches in
diameter, across the width of a room and 5 to 5½ feet above its
floor presumably served for hanging blankets and similar materials
as such poles still do in Pueblo homes. At least five second-type Late
Bonitian rooms (200, 203, 204, 209, 299) had been equipped with one
or two single poles of this sort. Of 16 two-pole racks noted, 4 occur
in Old Bonitian rooms (298B, 307-I, 315, 320) and obviously were
introduced after construction.

Pepper (1920, p. 223) describes a 3-foot-high shelf at the west
end of Room 62—three 4-inch-diameter logs, 2-inch poles above them,
and a reed mat lashed on top by means of cedar splints and yucca
thongs—and implies a second shelf at the east end. With little more
than standing room between, two such shelves would measurably increase
the storage capacity of a given room. Apparently such storage
shelves were more frequent in the upper rooms of Pueblo Bonito.

Unpublished Mindeleff photographs show seven, possibly eight,
close-lying pole seatings in the remaining north third of the west wall
of Room 179C a couple inches below a half-blocked ventilator, but
no provision had been made for a similar shelf in Room 180C, adjoining,
where two west ventilators remain open. Seven pole seatings
at lintel level of the southwest door in Room 185B and immediately
below a ventilator were not matched by like seatings in the
north half.

Seven-pole shelves may have been standard in upper storage rooms.
Mindeleff photographed such a series in the west half of the north
wall, Room 187C, at still level of the third-story west door—a series
that we carefully preserved during 1923 repairs (pl. 9, left) but
which subsequently was lost when the Braced-up Cliff collapsed.

Granaries.—In the traditional P. II arrangement of Old Bonito,

storerooms stood at the rear, behind the dwellings but connected with
them. On the earthen floor of remodeled Room 92, which is the
second story of 3a (elsewhere described as Room 97), Pepper (ibid.,
p. 298) found "a great deal of corn . . . bean bushes . . . still
green . . . and beans in the pod." These freshly harvested crops
may have been piled there temporarily, pending transfer to more
secure storage. Burned corn-on-the-cob and pinyon nuts were noted
in Room 5, a ground-floor storeroom. Stone-walled bins are described
in Room 85, some fitted with slab doors and built one upon another.

Late Bonitian housewives preferred jar-shaped storage facilities
in out-of-way places. Four outworn Corrugated-coil pots, one of
them containing a quantity of unidentifiable grass seed, had been
concealed under the floor of Late Bonitian Room 128. The five
Banded-neck cook pots buried to the rim beneath the floor of Old
Bonitian Room 323 were Old Bonitian and may have been placed
there in imitation of a contemporary Late Bonitian practice (Judd,
1954, pls. 50-51).

Subfloor jar-shaped pits also served for Late Bonitian storage.
We found five of them, averaging 42 inches in maximum diameter
by 54 inches deep under the floor of Room 266, each rimmed to receive
a discoidal sandstone slab at floor level. The five had been dug
into clayey sand so compact there was no need for a plaster lining.
Similar but smaller pits were exposed under Rooms 282 and 294
and still another, 46 inches in diameter by 50 inches deep, was noted
outside Room 177.

Milling rooms.—So far as we know, only two among the 300-odd
ground floor rooms in Pueblo Bonito, 90 and 291, were equipped with
binned metates for grinding the daily ration of maize. Both were
Late Bonitian rooms and both had been stripped of their mills and
bin slabs at the time of abandonment or before. We observed no
trace of a milling bin in first-story Old Bonitian rooms and Pepper
mentions none. Obviously the housewives of Pueblo Bonito kept
and used their metates in second- and third-story living rooms.

All Pueblo Bonito metates are of sandstone, troughed, and open
at one end. None has an over-all grinding surface such as that from
Room 5, Pueblo del Arroyo (Judd, 1959, p. 106). Mills of the Old
Bonitians, to judge from Pepper's observations and our own, are
broad, thin, and shallow-grooved—more deliberately trimmed, perhaps,
but otherwise comparable to the tabular metates of Chaco
Canyon BM. III and P. I. peoples (Roberts, 1929, p. 132; Judd,

1924, p. 402)—while those of the Late Bonitians were 4 or 5 inches
thick, large and heavy, sometimes too bulky for a strong man to turn.

Fireplaces.—Of all the hearths on which Bonitian meals were prepared,
we have record of only 69, all but two in ground-floor rooms.
Twenty-five occur in 16 Old Bonitian dwellings; 44 in 36 Late
Bonitian houses. Some were situated in the middle of the floor,
more or less; others ranged along the wall or in a corner. Irrespective
of placement, most of our 69 fireplaces were slab-lined and
circular, or nearly so; 14 were lined with masonry and plastered; 5
were equipped with sandstone fire dogs; 7, including that in Old
Bonitian Room 330, were rimmed with adobe.

Late Bonitian architects built Rooms 91 and 92 upon the walls of
Old Bonitian Rooms 3 and 3a. A fireplace in second-story Room 91
is described by Pepper (1920, p. 40) as slab-lined; the one in 92 as
shallow and probably rimmed with adobe (ibid., p. 299). Since the
bottom of this latter was no more than a thin layer of mud spread
directly upon the pine poles and brush ceiling of 3a, it is surprising
there had not been another destructive conflagration here. Inadequate
protection from second- and third-story hearths probably
accounted for most of the fires cited by Pepper.

What my notes describe as "fire pits," thus to distinguish them
from domestic hearths, are of Late Bonitian construction but unknown
function. We came upon seven of which these four are thoroughly
typical: (1) In Room 221, an open-air work space, pit 3 feet 7
inches east-west by 28 inches wide and 31 inches deep, masonrylined,
filled with scorched sand and a scattering of charcoal; (2) 27
inches outside the southwest corner of Room 314, slab-lined pit 31
inches north-south by 21 inches wide and 27 inches deep, surrounded
by flagstones; (3) north of Kiva X on the last recognizable West
Court surface, masonry-lined and plastered pit 3 feet 8 inches wide
and originally 5 feet 7 inches north-south but subsequently divided
by a 2-foot-thick partition and both sides continued in use (pl. 17,
upper); (4) Kiva R roof level north of the Kiva Z enclosure, 5 feet
north-south by 35 inches wide by 49 inches deep, masonrylined
and plastered (pl. 18, left). The plaster of this latter was reddened
by fire but not fused; sand and sandstone spalls filled the lower
2 feet, sand with bits of charcoal the remainder. Three others were
noted subfloor: two in Room 215 and one in Room 220. In each
of the seven instances there were no potsherds among the fill; no
bone fragments, burned or unburned. Three pits were oriented northsouth
but their dimensions varied.

Conflagrations.—Pepper repeatedly cites evidence of fire in rooms
excavated by the Hyde Expeditions, and we noted other instances
of charred timbers, smoke-blackened walls, and burned sand upon
the floor. Fire was an understandable hazard of occupancy, but the
possibility of fires set by raiding parties long after desertion of the
village is not to be dismissed lightly. Throughout the Plateau
Province one may hear tales of ancestral Navaho, Ute, and Apache
warriors who drove the Cliff Dwellers and contemporary peoples
from their homes and then fired the buildings. Holsinger (MS.,
p. 17) may have been echoing such a story when he reported that about
40 rooms in the two easternmost rows at Pueblo Bonito had been
burned, presumably by enemies.

Whatever the cause, fire had gutted many of these east-side rooms
some time after they were vacated. In Room 257, for example, sand
varying in depth from 19 inches at the north end to 27 inches at the
south had collected upon the floor before the ceiling burned and
collapsed.

Wall plaster in Room 260 was fire-reddened above a sand deposit
several inches deep. Blown sand 4½ feet in depth filled the southwest
corner of Room 266 sloping thence to 18 inches in the opposite corner.
Charred timbers lay upon that sand with more blown sand above
the timbers and then masonry fallen from the second and third stories.
The third-story south wall of Room 171 had collapsed and fallen
outward and its outermost building stones inexplicably were overlain
by a layer of burned sand, sticks, and cedarbark—a post-abandonment
accumulation.

Pepper (1920, fig. 131) pictures 11 Late Bonitian pitchers on
the floor of Room 99 half buried by stratified sand and only the
exposed portions burned. When we cleared Old Bonitian Room 298
we learned that fire had destroyed both the first- and second-story
ceilings but had barely scorched a blanket of wood chips spread over
the lower floor. Whether these evidences of fire at Pueblo Bonito
point to domestic carelessness or to post-occupancy raids is open to
question but there can be no doubt that such flimsy hearths as those
in Rooms 91 and 92 were ever-present dangers.

Wind-borne sand.—Sand is everywhere present in Chaco Canyon
today, and wind-blown sand obviously was a daily annoyance to the
housewives of Pueblo Bonito. It blew through open doors and sifted
through ceilings. When Pepper entered Room 3 he found 2 or 3
feet of sand upon the floor; sand was 3 to 4 feet deep in Room 3a;
4 to 12 inches deep on the floor of Room 92 (second story of 3a).

Six feet of wind-borne sand had piled up against the rear wall of
Old Bonitian Room 5 before the Late Bonitians built Room 203 upon
that sand (fig. 14). Sand continued to accumulate while second-type
masonry was in vogue. Around on the west side of the village it
had accumulated to a depth of 3 feet 9 inches above approximate
floor level of 3 unexcavated and unnumbered second-type rooms before
Late Bonitian architects began their third-type Room 117
(pl. 37, upper).

Chaco Canyon's inexhaustible sand is carried on the prevailing
upcanyon winds by day and back again at night, but our efforts to
measure its rate of deposition proved unsuccessful. By early June
one season a foot of sand had settled in the lee of a packing box I
had anchored 50 feet west of Room 115 the previous fall and an unknown
quantity had blown unchecked across the top. Bryan (1954,
p. 21) estimated that 4-6 feet of blown sand had collected on the north
side of Pueblo Bonito during the period 1900-1921 or at the rate of 3
inches a year. My own guess would double that rate. Wind-borne
sand bulked large in every stratigraphic section we laid bare, including
those in the two south refuse mounds.

Until 1903 when wind-blown sand barred the way, Hyde Expedition
freight wagons traveled the old Farmington road across the
mouth of Escavada Wash and northward (Bryan, 1954, fig. 1).
Later, a substitute road left the Chaco by way of Mockingbird Canyon;
still later, and currently, by way of the rocky Rincon del
Camino. In 1920 drifted sand forced our reconnaissance wagon, oldtime
freighter Jack Martin at the whip, far out into the arroyo channel
as we left Chaco Canyon, crossed the Escavada, and turned
toward Farmington.

Defensive measures.—Bonitian families had scant protection
against wind-driven sand, but they did their best to guard against
marauding enemy bands. There was no door in the outside, rear wall
of Old Bonito, but outside doors were provided for each room, upper
and lower, in the 2-story row of second-type-masonry houses the
Late Bonitians built to enclose the old settlement. And each of these
Late Bonitian doors, to judge by the duplicating stonework, was
sealed almost immediately and left sealed. Not until the 19th century
was that blocking masonry pried loose (pls. 19, right; 26, upper).

In their next two constructional programs Late Bonitian architects
presumably allowed only three external first-story doorways,
those in Rooms 118, 154, and 155, and each of these likewise had
been blocked. Only one outside second-story door was permitted so

far as we know, that in Room 182B, (pl. 13, right) and none at all,
apparently, in third- and fourth-story rooms. Neither Jackson's description
nor Mindeleff's 1887 photographs offer any evidence of an
outside balcony, as at Chettro Kettle and Pueblo del Arroyo. Lacking
external doorways to family apartments and with only one common
gateway to the village, Pueblo Bonito was virtually a walled
town.

The sole entrance to Pueblo Bonito, that in the southeast corner
of the West Court between Rooms 137 and 140 (fig. 2), was originally
7 feet 10 inches wide. After an unknown interval this passageway
was barred by a single crosswall with a 32-inch-wide door
in the middle. Later, this reduced opening was blocked to leave,
front and back, shallow alcoves presumably sheltering ladders to be
pulled to the rooftops in time of need. There must have been pressing
reason for this deliberate and progressive closing-in!

What is now represented to visitors as a second village gateway,
in the southwest corner of the East Court is an error for which I am
partially responsible. Room 155, previously cleared, had been refilled
with excavation waste thrown out of 152. When we carted away this
waste to make grade for our dump cars and track we removed some
of the broken masonry, disintegrated and much reduced in the interval
since excavation (pl. 5, upper). The south door of Room 155,
shown open with sill at floor level on unpublished Hyde negative
570, presumably had been blocked during occupancy as was that
in Room 154, adjoining. My failure partly to restore these broken
walls left a low place between Rooms 154 and 156 that furnished
some one with the idea of a second village entrance, balancing that
to the West Court. On the other hand, Jackson's 1877 restoration
of Pueblo Bonito shows a broad East Court gateway hereabout (pl.
49, upper).

The blank outside wall of Old Bonito, the promptly sealed doors
in the initial Late Bonitian addition to the pueblo and omission of
external doors thereafter, the barring of the lone town gateway, and
evidence of prehistoric vandalism in Old Bonitian burial rooms
(Judd, 1954, pp. 325-341), all combine to suggest early and recurrent
hostile pressure against the inhabitants of Pueblo Bonito. The
source of that pressure is conjectural, but it may well have been the
Largo-Gallina area 100 miles to the northeast, whence came, presumably,
the conical-bottomed pots we recovered from Kiva W and
Room 314 (Judd, 1954, p. 195).

All Late Bonitian dwellings, including 314, had been stripped of

their contents and vacated. This fact might be interpreted as evidence
of internecine strife but post-abandonment fires and the plundering
of eight Old Bonitian burial rooms were not the work of
neighbors. There are those who argue that harassment from nomadic
groups rather than drought or impoverished soil initiated the
Pueblo III exodus from the San Juan drainage, including Chaco
Canyon. Others argue as convincingly that intramural quarreling,
as happened at Oraibe in 1906, could have spurred abandonment of
the northern mesas and valleys. Together internecine strife, or external
harassment, plus droughts and impoverished soil would have
proved a combination no superstitious Pueblo farmer could withstand.

During our study of Bonitian architecture we collected portions
of 97 constructional timbers—not all we might have collected, as
we know in restrospect, but what seemed at the time as an adequate
selection of those we happened upon. The science of dendrochronology
has advanced since its crude beginnings at Pueblo Bonito in
1922, and the samples we took for Dr. Douglass will reveal more
than their dates as research upon them continues at the University
of Arizona. Two former Douglass students, Terah R. Smiley and
Bryant Bannister, have recently reviewed our 97 specimens, here
listed by their original field number (the JPB numbers of Douglass
publications), source, and masonry type and have revised several terminal
dates previously announced.

TREE-RING DATES FROM PUEBLO BONITO

Field No.			Masonry type
Field No.	Room	Location	1	2	3	4
1	245	Subfloor chamber, south end			1050
2	227	Beam end from R. 173 [same as K-9; H-16 collected by E.H.M.]				1078
3	227	E-W beam [K-8]				1075
03	227	Beam end from R. 173				1076
003	227	Beam end from R. 227-I				1053
4	244	Beam fragment				decayed
5	244	Beam fragment				1060
6	244	Beam fragment				1097
7	244	Beam fragment				1078
8	244	Beam fragment				1078
10	256	Charred fragment				1050
14	257	Above blown sand, south of wattled wall				1081
15	257	Above blown sand, south of wattled wall				1124
16	257	Above blown sand, south of wattled wall				1047
17	257	Above blown sand, south of wattled wall				1126
18	257	Above blown sand, south of wattled wall				1080
19	257	Above blown sand, south of wattled wall				1083
20	257	Above blown sand, south of wattled wall				juniper
21	257	Above blown sand, south of wattled wall				juniper
22	227-I	Charred beam fragment				1064
23	227-I	Charred beam fragment				1081
24	242					1080
25	242					1081
26	—	—				—
27	268	Rectangular post, west wall slot			1080
28	162	Pilaster log, south side			juniper
29	162	Pilaster log, south side			juniper
30	162	Pilaster log, south side			juniper
31	162	Pilaster log,			juniper
32	162	Pilaster log,			juniper
33	162	Pilaster log,			juniper
34	162	Pilaster log,			juniper
35	259					juniper
36	Kiva J	Pilaster No. 4			juniper
37	Kiva J	Pilaster No. 5			1080
38	Kiva C	Pilaster No. 8			1120
39	Kiva H	Pilaster No. 2			juniper
40	Kiva H	Pilaster No. 8			1054
41	161	Pilaster No. 7			juniper
42	Kiva B	Pilaster No. 4			1063
43	Kiva B	Pilaster No. 5			1055
44	Kiva B	Pilaster No. 2			juniper
45	Kiva B	Pilaster No. 3			juniper
46	264	Beam			1040
47	62(?)	Hyde dump, north side Kiva G
48	57	Beam end, north wall				1071
49	55-57	Stringer in wall between				1083
50	251	S. jamb post, east door to R. 250			juniper
54	—	Beam, Wetherill store, outside R. 14b				1035
55	228	E beam, N-S pair, south end				1073
56	228	E beam, N-S pair, north end				1073
57	228	W beam, N-S pair, north end				complacent
58	228
67	292	Beam from R. 293			920
68	296		932
69	296		1047
70	Kiva L	Roofing pole			1061
71	Kiva L	Roofing pole			complacent
72	Kiva L	Roofing pole			complacent
73	Kiva L	Roofing pole			complacent
74	Kiva L	Roofing pole			complacent
75	298		cottonwood
76	—	North of R. 295				1041
77	—	North of R. 295				complacent
78	—	North of R. 295				complacent
79	290-291	Beam under South wall (across N arc Kiva L)			1061
80	3c(?)	[R. 111A] beam	cottonwood
81	Kiva L	Roofing pole, 12th layer from top			1047
82	6	Post step at south door	decayed
83	305	Beam fragment		1033
90	308	Beam fragment		complacent
91	308	Beam fragment		complacent
92	Kiva P	Pilaster log			juniper
93	Kiva L	Pilaster No. 1			1011
94	Kiva L	Pilaster No. 6			juniper
95	—	Wetherill "gas house"				1057
96	—	Wetherill "gas house"				1062
97	286	Subfloor kiva, post, east side			1088(?)
98	286	Subfloor kiva, post, east side			1091
99	—	Fallen tree, southeast corner, West Court (A.D. 983)
104	317	Ceiling pole	828
105	317	Ceiling pole	859
106	325	Post, southeast corner	919
107	320	Beam [3-4″ E-W beam]	919
108	320	Beam [3-4″ E-W beam]	919
109	320	Beam [3-4″ E-W beam]	919
110	—	Ceiling pole, narrow space west of R. 320B		complacent
113	325	Post, northeast corner	919
114	323	Beam	935
115	323	Beam	935
116	323	Post under beam No. 114	919
117	323	Post under beam No. 115	919
118	327	Beam
120	327	Beam from R. 325
122	Kiva X	Beam from west, 5″ dia.			1034
123	Kiva X	Beam			—
130	261	Beam [prob. from R. 267]			1070(?)
145	314	Beam above fill in OB room			complacent

As will be noted from the foregoing, the National Geographic
Society collected at Pueblo Bonito samples of 97 constructional timbers
in 33 rooms and 9 kivas. Of this total, however, 38 (40 percent)
were not datable, either because the growth rings were too uniform
("complacent" in the Douglass terminology) or because the
wood—juniper, pinyon, or cottonwood—is not yet readable. Of the
remaining 59 specimens, 13 came from Old Bonitian houses and,
except one reused 1047 beam, their cutting dates range from A.D.
828 to 935. Seven of these dates are identical, A.D. 919.

Seventeen specimens felled between 1011 and 1120, including a
second obviously reused example dated 920, were collected in thirdtype
rooms, and 28 other specimens, all cut between 1035 and 1126,
came from fourth-type structures. Room 305 is our only dwelling of
second-type masonry yielding a datable timber, a single specimen
felled in A.D. 1033.

Thus, excepting the two clearly salvaged, the Pueblo Bonito Expedition's
59 datable timbers fall into two groups, one bracketing the

years A.D. 828 to 935 and the other 1011 to 1126. The first group
is from Old Bonitian structures and the second, from Late Bonitian
houses. Together, the 59 are too few in number to have more than
a suggestive value but they do suggest periods of constructional
activity.

If 107 years seems too short a period for the building of Old
Bonito, with its 8 feet of rubbish piled out in front, it is to be
remembered that our bracket is based upon 13 specimens only, all
from larger rooms where pine and fir logs were utilized. Among
Hyde Expedition beams submitted to him for cross dating with
Aztec Ruin, Douglass (1921, p. 30) noted two from Rooms 32 and
36 in the north-central part of the old pueblo. Both, unfortunately,
remain undated.

It will be observed also that two or more timbers with the same
cutting date were recovered in only four rooms and that three of
these (320, 323, 325) are in Old Bonito. (A previously sawed log in
Room 228 was sampled twice.) Two pine beams from Old Bonitian
Room 323, both felled in A.D. 935, had been propped with posts cut
16 years earlier. Reuse seems undeniable. Reuse, even repeated
reuse, of constructional wood is a long-established Pueblo practice,
as is the stacking of logs against future need.

In his review of material collected in Hopi villages by the second
Beam Expedition, that of 1928, Douglass (1939) remarked that some
of the logs represented had been in use for hundreds of years and were
noticeably worn in consequence. While this may have been equally
true of some of the pinyon and cottonwood logs from smaller rooms
of Old Bonito, none of the pine and fir timbers we recovered, large or
small, exhibited wear in any appreciable degree. They had been cut,
peeled, and used without delay.

Our 46 dated timbers from Late Bonitian structures represent
a very small portion of the total required to roof Pueblo Bonito.
That total numbered in the thousands. Over 300 logs, long and
short, were utilized in the cribbed ceiling of Kiva L and Kiva L was
only one of perhaps 30 Late Bonitian kivas in use contemporaneously.
In addition there were the dwellings and storerooms of a
thousand people, more or less.

The JPB 99 of our list is from a much decayed pine that had stood
at the south end of the West Court while Pueblo Bonito was inhabited
(pl. 1). Initially Douglass (1935, p. 47) gave this fragment a
tentative date of A.D. 1017 ± 35, but in a later review Smiley fixed
the outermost surviving ring at 983. One may only guess at the number

of annual rings lost through disintegration but that lone, midvalley
straggler from the Chaco forest obviously witnessed the unfolding
of much Pueblo Bonito history.

Added to those we recovered within the walls of Pueblo Bonito,
our list includes three samples, JPB 54, 95, and 96, from fine old
timbers in buildings Richard Wetherill erected between 1897 and
1910. The first of these, JPB 54, identifies a beam from the trading
post Wetherill built in the autumn of 1897 outside Room 14b (Pepper,
1920, fig. 4) and which we razed in 1923; JPB 95 and 96 are beam
samples from a square, isolated stone building that is identified on
Holsinger's 1901 plan of Pueblo del Arroyo as "employees quarters"
(Judd, 1959, fig. 45) but which Jack Martin, a Hyde Expedition
teamster, called "Wetherill's gasoline house." This same small building
is listed as "Tanner's garage" for specimens 2345 and 2346, both
with a cutting date of 1065, collected for Gila Pueblo in 1940 by Dr.
Deric O'Bryan.

O'Bryan (personal communication) also sectioned six ceiling poles
in Room 97, a 2-story Old Bonitian room revamped by the Late
Bonitians, and reported cutting dates at 1026, 1057, 1067, 1071, 1073,
and 1092. Four timbers from another second-type room, 300, were
dated 1029, 1040, 1044, and 1047. Gila Pueblo employed a mechanical
method for counting rings but the results obtained rarely varied more
than a year or two from those recorded by Douglass.

O'Bryan for Gila Pueblo is among those who have collected treering
material in Chaco Canyon since conclusion of the Pueblo Bonito
Expeditions in 1927. He lists two constructional dates from Rooms
239 and 240, respectively, on the periphery of Kiva D, one (No. 2291)
collected by G. Vivian in 1940 while repairing the southwest bench
in Kiva F, and several from timbers, provenience unknown, utilized
by Richard Wetherill in reroofing Bonitian rooms for his own use.
Timbers that were sound, unscarred, and unclaimed were there for
the taking when Wetherill came to establish his home in treeless
Chaco Canyon and, however much we may regret the fact today, I am
not among those who condemn him for having taken advantage of
his opportunity.

Bryant Bannister (1960) dates at A.D. 1030, 1031, and 1077 three
beams recovered by National Park Service personnel during demolition
of "Ackerly House," the former Wetherill dwelling and store at
the southwest corner of Pueblo Bonito (pl. 5, lower). Despite field
numbers since added, the original National Geographic Society list
ended with JPB 145, as indicated above.

Plate 6

Left: A stratigraphic
test 20 feet
deep, West Refuse
Mound.

(Photograph by
O. C. Havens,
1921.)

Right: An exploratory
West
Court trench revealed
razed buildings
and an Old
Bonitian trash
heap.

(Photograph by
O. C. Havens,
1925.)

Plate 7

Upper: Pueblo Bonito from the north cliff. Pit No. 3 lies at left of the path, mid-way between
ruin and camp.

Lower: Beginning West Court excavations. North wall of Room 133 in foreground.

(Photographs by O. C. Havens, 1924.)

Plate 8

The East Court at Pueblo Bonito as it may have appeared about A.D. 1050.

(From the original drawing of Kenneth J. Conant, 1926.)

Plate 9

Repairing north wall of fourth-story Room 189D. At right,
holes for 7-pole storage shelf, Room 186C, and repaired areas
(lighter stonework).

(Photograph by Neil M. Judd, 1923.)

National Geographic Society repairs in third-story Room 180C;
ceiling-pole level of Room 179 in foreground.

(Photograph by Neil M. Judd, 1921.)

1. Spalled-sandstone slabs of wall width laid in
abundant quantities of mud and often protected
from the elements by closely placed stone chips.

2. Rubble veneered with casual blocks of friable
sandstone dressed on the face only and chinked all
around with chips of laminate sandstone.

3. Rubble veneered with matched blocks, either of
laminate or dressed friable sandstone or both, alternating
with bands of inch-thick tablets of laminated
sandstone.

Plate 10.—The four principal types of masonry at Pueblo Bonito, each represented by a
2-foot square section.

4. Rubble veneered with laminate sandstone of
fairly uniform thickness laid with a minimum of
mud plaster between.

Plate 11

Left: South end
of Old Bonitian
Room 326 with
small T-shaped recess
in secondstory
wall.

Right: Smallstone
protection
against rain and
wind-blown sand,
exterior of Old
Bonitian Room 102.

(Photographs by
O. C. Havens,
1924.)

The ceiling of Late Bonitian Room 14b included a layer of hand-smoothed willows.

Plate 12

A typical Old Bonitian ceiling usually contained a layer of chico brush.

(Photographs by O. C. Havens, 1924.)

Plate 13

Left: Late Bonitian
door fitted
with secondary
jambs for retention
of doorslab from
Room 243.

(Photograph by
Neil M. Judd,
1926.)

Right: Blocked
outside door, Room
182B. First-story
beam ends were
severed flush and
plastered over.

(Photograph by
O. C. Havens,
1925.)

THE RISE AND FALL OF PUEBLO BONITO

Pueblo Bonito began as a wide-spreading crescent of Pueblo II
houses with storerooms at the rear, several subterranean kivas out in
front, and the village trash pile beyond. After that trash had accumulated
to a depth of 8 feet or more, after 5 feet of sand had
settled against the old P. II houses, another people came to join the
original settlers—a Pueblo III people with a more advanced architecture
and a different pottery complex. Together, the houses these
P. III people built and the pottery they made are now widely accepted
as earmarks of a distinct social development, "The Chaco Culture."
One objective of the Pueblo Bonito Expeditions was to ascertain, if
possible, the origin of this development and its termination.

We reached part of our goal but not all. After seven summers at
Pueblo Bonito, 1921-1927, I am of the opinion that the P. II and the
P. III peoples who formerly dwelt there had come independently from
beyond the San Juan River, but I can only guess at their destination
after leaving Chaco Canyon. This recognition of the broad area north
of the San Juan as the place of origin—an area in which I have done
no field work for many years—has been substantiated by the published
observations of Kidder, Morris, Martin, Roberts, Brew, and others,
and I have placed great confidence in those observations in what
follows. I am aware of no later, equally pertinent researches.

The so-called Chaco Culture was just short of full bloom when
it first came to Chaco Canyon. At Pueblo Bonito it introduced veneerand-core
masonry and architectural precision; it also introduced
Corrugated-coil Culinary ware, Straight-line Hachure and, among
others, a hybrid variety of domestic pottery we designated "the ChacoSan
Juan." Seen by various observers and variously described, the
Chaco Culture and influence attributed to it have been reported far
beyond the borders of Chaco Canyon.

Chaco-like pottery and Chaco-like masonry have been cited repeatedly
as proof that Lowry Ruin, northwest of Mesa Verde
National Park and Aztec Ruin to the southeast, among others, represent
colonies from Chaco Canyon. Mancos Black-on-white and
McElmo Black-on-white were dominant pottery types at Lowry
although Mesa Verde Black-on-white appeared conspicuously in the
upper fill of several rooms (Martin, 1936, p. 94, 205). All Lowry
masonry is of veneer-and-core, or double-coursed, composition but
Martin separated it into 3 classes: Chaco-like, non-Chaco, and intermediate.
Tabular sandstone identifies the first; squarish blocks of

friable sandstone, the second; blocks so irregular as to prevent
uniform coursing, the third.

Aztec Ruin, with its predetermined ground plan, its large highceilinged
rooms, and kivas sunk within the house mass is even
closer to Chaco architecture than Lowry. Like the latter, however,
Aztec masonry falls short of the Chaco ideal because building stone
comparable to that of Chaco Canyon is not found in the vicinity.
Aztec sandstones, and those generally throughout the northern
country, are tough and cross-bedded; they lack the natural cleavage of
Chaco sandstones.

Eventually both Lowry and Aztec were abandoned by their builders
and thereafter were appropriated, partially repaired, and reoccupied
by Mesa Verde peoples. This was also true of Solomon's Ruin, on the
south bank of the San Juan River, and of various lesser structures to
the northward. So-called Chaco peoples settled this northern country
first and those with a Mesa Verde-like culture moved in later.
Where remains of the two occur at the same site "the Mesa Verde is
always on top" (Morris, 1939, p. 204)—not Classic Mesa Verde
necessarily but its forerunner.

The range of Chaco-like influences and the occurrence of Chacolike
pottery and Mesa Verde-like pottery in the same river valleys
and even in the same ruins were puzzles Earl Morris took for
his own. No one did more than he to define and interpret the factors
in these puzzles. He recognized the West Pueblo at Aztec Ruin as a
Chaco-type building but regarded the pottery of its builders as no
more than "Chaco-esque." He recognized the contemporaneity of
"true Chaco," "Chaco-like," and "non-Chaco" earthenware throughout
La Plata Valley (Morris, 1939, p. 205). Chaco-like pottery and
masonry were especially noticeable at his Sites 36, 37, 39, and 41 and
each of these had been reoccupied by peoples with a Mesa Verde-like
culture.

On his plan of Aztec Ruin, Morris (1924) includes the local Great
Kiva and 28 lesser kivas. Of these latter, 12 are represented with
shallow basal recesses, 8 to 10 pilasters, and subfloor ventilators. Two
(C, N) are shown with the deep south banquette that identifies them
with the period of Mesa Verde, or a proto-Mesa Verde, occupancy. I
use "proto-Mesa Verde" as a synonym because, unlike others, I see
only one Mesa Verde-like culture for the Mesa Verde country—a
culture born in small-house settlements westward toward the Rio
Colorado or beyond, a culture that developed vigorously in McElmo
Canyon and its numerous tributaries along the Colorado-Utah border

and culminated on the Mesa Verde itself in such composite cave
communities as Spruce-tree House and Cliff Palace, with their distinctive
pottery and numerous ceremonial chambers or kivas.

So-called Mesa Verde-type kivas may differ from place to place
but they retain as fairly constant fixtures an encircling bench about
3 feet high, six masonry pilasters rising 2 to 3 feet higher, a deep
above-bench recess or "banquette" at the south with a floor-level
ventilator underneath and, between fireplace and north bench, a
cylindrical hole in the floor, the sipapu, symbolic passageway from
the underworld (Kidder, 1924, p. 60).

Chaco Canyon kivas, on the other hand, have low, log-enclosed
supports for their cribbed ceilings rather than 3-foot-high masonry
pilasters. They have a shallow in-bench recess at the south, a subfloor
ventilator connecting with an external shaft, and a sunken
"vault" of unknown function west of the fireplace. They lack the
deep, above-bench south banquette of Mesa Verde kivas and they lack
the sipapu. In all the Society's Chaco Canyon investigations no
kiva-floor hole was found that could positively be identified as a
sipapu except, possibly, that in Kiva Q. But, as we shall see, both
Mesa Verde-type and Chaco-type kivas occur at Pueblo Bonito.

Throughout the Mesa Verde country and southward many archeological
sites, early and late, display a mixture of elements considered
distinctive either of the Mesa Verde culture or the Chaco. Morris's
Site 39, at the junction of La Plata River and Barker Arroyo, includes
a number of buildings evidencing occupancy from BM. III to late
P. III, or Mesa Verde, times (Morris, 1939, pp. 50-55). Building I,
a late structure, is noticeably Chaco-like in its planned arrangement;
refuse piled on the north side contained many sherds that "in quality
of paste, surface treatment, and ornamentation, might have come
from the dump of Pueblo Bonito." But, the smaller of its two intramural
kivas, No. 6, had eight masonry pilasters 3 feet high, a subfloor
ventilator, a shallow basal recess at the south, and a 39-inch-deep
banquette above—a combination of Chaco-like and Mesa Verde-like
fixtures.

Beneath Building I were remains of a Pueblo II cobblestone
structure that included four small kivas of which Morris cleared two.
One of these was typical of the Mesa Verde but its companion, Number
1, had a 9-inch-wide bench without pilasters, a south recess 6
inches deep, a sipapu, and an under-floor ventilating system—the only
instance, if I read correctly, in which a subfloor ventilator is reported
in a Pueblo II kiva. Here, then, as in the overlying Pueblo III building,

architectural features that later came to distinguish Mesa Verde
and Chaco-type kivas appear together in the same chamber.

Presumably all circular kivas, irrespective of period and locality,
evolved from BM. III—P. I pit-houses wherein family living quarters
were combined with an area set apart for rituals. Brew (1946)
describes 14 such combinations at Site 13 on Alkali Ridge, southeastern
Utah. No two are exactly alike. With one exception (N)
all had four roof-supporting posts, a restricted area at the south,
and a low passageway to an antechamber. Some had a sipapu or
possible sipapu; 3 (B, E, M) were lined at floor edge with 2-inchdiameter
posts, upright or leaning inward; one (H) had a threequarter
bench and upright posts at the rear of it.

Small posts slanting roofward from the rim of a pit-house,
or from its "bench" when the pit was deeper, are characteristic
of the Pueblo I period. They have been noted, north and south,
wherever pit-dwellings are known and will be cited again in our
description of P. III kivas at Pueblo Bonito. By their own charred
timbers, a majority of dated pit-houses apparently were constructed
in the 8th century. As previously noted, at least two of them occur in
Chaco Canyon.

One-story surface structures walled by posts packed between
with mud—a specialty of Pueblo I architects—often accompanied
BM. III and P. I pit-dwellings. Roberts (1930) describes three different
kinds of post-and-mud structures in the Piedra district, east of
the Mesa Verde, each kind grouped crescentically about the north and
west edges of the pit that supplied mud for house walls. Pueblo I
post-stone-and-mud construction persisted on Alkali Ridge even
after local pottery had developed into types generally recognized as
Pueblo II (Brew, 1946, p. 222). Rocks crowded into the mud between
posts led to coursed stonework and single-coursed masonry has
long been regarded, sometimes incorrectly, as a badge of Pueblo II
civilization.

Lancaster and Pinkley (1954) describe a remarkable sequence
of three superposed P. II kivas at Site 16, Mesa Verde National Park,
each provided with sipapu and lateral ventilator. The first was a
simple 4-post jacal structure while the second was walled with "singlecoursed"
masonry and the third, with "double-coursed" stonework
including blocks dressed by pecking. Alone among the three, this
uppermost Site 16 kiva possessed masonry pilasters (eight in number,
2 feet high) and a deep south recess—features that thenceforth
were to distinguish Mesa Verde kivas.

On the basis of our explorations at Pueblo Bonito the two bark
dates, A.D. 1074, cited by Lancaster and Pinkley (ibid., p. 78)
seem to me a bit late for a Pueblo II building although quite in keeping
with "double coursed" masonry. Both single- and double-coursed
stonework appear at Pueblo Bonito, but the latter was not introduced
until after 8 feet or more of household rubbish had accumulated in
front of the original settlement. That original settlement was a
crescent-shaped Pueblo II village of single-coursed masonry; 12 of
the 13 datable timbers we recovered from its ruins were felled between
A.D. 828 and 935. In contrast, beams, ceiling poles, and lintels
salvaged from later portions of the same pueblo, those with doublecoursed
masonry, bear tree-ring dates from A.D. 1011 to 1126.

These latest rooms, despite their superior construction, were
first to be abandoned as I read the record, and they were stripped
of their furnishings in the process. The Old Bonitians, on the other
hand, remained in residence and amassed the cultural treasures
and the foodstuffs cataloged by the Hyde Expeditions. If eight Old
Bonitian rooms eventually were converted into burial vaults for a
hundred dead that could not be interred in the accustomed place the
fact merely evidences continuing occupancy under adverse conditions
(Judd, 1954, pp. 325-341). We found no adult burial in Late
Bonitian dwellings.

Pueblo II masonry at its very best is found in Old Bonito—its
equal has not been reported elsewhere—wall-wide slabs of sandstone
spalled around the edges and bedded one upon another in a surplus
of mud mortar (pl. 10, 1). Interior walls may include upright
slabs at the base or posts with mud and rocks between in the old
P. I. tradition; exteriors may slant inward after the manner of pithouse
walls and may be studdied with stone chips, presumably to
lessen erosion by wind and water.

In his tabulation of architectural features observed on Alkali
Ridge, Brew (1946, pp. 204-205) notes that 8 of the 14 BM. III—P. I
pit-dwellings at Site 13 were equipped with 4 roof-supporting posts
while five had six posts each and one (N) had none. Nine Pueblo II
kivas on Alkali Ridge, like nearby pit-houses, had been dug down into
native earth and plastered. Each of the nine was provided with a
lateral, above-floor ventilator; the sipapu was present in five and
absent in four; the deep south banquette appeared in two only, those
at Site 11 and in Unit 2, Site 13.

Five of Brew's nine P. II kivas had six masonry pilasters each, two
had eight, one had four, and the ninth retained the four free-standing

posts that preceded pilasters. Roberts (1939, p. 35) advances the very
plausible thought that stones piled behind a weakened roof support
led to masonry pilasters and that these latter eventually supplanted
posts altogether. Kivas at Brew's Sites 3 and 9, one with four masonry
pilasters and the other with four roof-supporting posts, were both
bowl-shaped and seem likely forerunners of the bowl-shaped P. II
kivas at Old Bonito.

From his investigations at Whitewater, Roberts (1939) points to
two bench-wide adobe ridges in Structure 12 as possible antecedents
of the low Chaco-type pilaster and to the subfloor ventilator in
Kiva B, Unit 2—the only one observed at Whitewater—as one of the
earliest of its kind. Both Kiva B and Structure 12 are described
as Developmental Pueblo, or P. II; both were provided with the symbolic
sipapu. But the subfloor ventilator was installed when Kiva B
was reconditioned and a new floor laid. The possibility remains, therefore,
although Roberts does not hazard the guess, that this renovation
of a P. II kiva occurred coincident with construction of two nearby
P. III house units and a Great Kiva, each of which possesses undeniable
Chaco affinities and may be more or less contemporaneous with
the Village of the Great Kivas on the Zuñi Reservation, which is
definitely P. III in time and possibly even post-Bonito (Roberts,
1932, p. 169).

The subfloor ventilator in the P. II kiva beneath Morris's Building
I, Site 39, appears to be fully developed (Morris, 1939, p. 53).
Since there is no hint here of reconstruction, this second example may
be older than that in Roberts's rebuilt Kiva B. In either case the two
apparently identify the subfloor ventilator—one of the most pronounced
differences between Mesa Verde and Chaco kivas—as a P. II
innovation. I know of none earlier. Two earthenware vessels crushed
upon the floor of his buried kiva are also identified by Morris as
Pueblo II.

There is still disagreement as to the actuality of P. II pottery
just as there is dispute as to what constitutes Mancos Black-on-white
and McElmo Black-on-white. Martin (1936, pp. 80-94) first described
Mancos Black-on-white from Lowry Ruin where it was
present "from earliest times, rising and then gradually decreasing in
percentage" and, as it decreased, McElmo Black-on-white, "formerly
known as proto-Mesa Verde," rose in favor (ibid., p. 113). In part
because these two varieties were associated at Lowry, Martin classified
the ruin as "late P. II—early P. III" in time and culture but with
strong Chaco affiliations. Indeed, his Mancos Black-on-white resembled

Chaco pottery so closely he was sometimes undecided whether
a sherd in hand was one or the other (ibid., p. 112). The nine known
tree-ring dates from Lowry, A.D. 987-1086 (Smiley, 1951, p. 23), lie
within the Pueblo Bonito bracket.

Presence of Mancos and McElmo pottery in association at northern
ruins has long puzzled archeologists of the Pueblo area. Both are
primarily sherd-tempered, but the one is ornamented with mineral
paint and the other with organic. Mineral paint persisted from P. I
through the Chaco-like phase of P. III, but meanwhile the use of
organic paint increased progressively and became dominant by the
end of the period, when Classic Mesa Verde was in its prime
(Shepard, 1939, p. 254).

From Mesa Verde National Park Deric O'Bryan (1950) contributes
to the definitions of both Mancos Black-on-white and McElmo
Black-on-white. He identifies the first with small, one-kiva house
units dated approximately A.D. 900-1050; the McElmo Phase, about
1050-1150, is identified with larger masonry settlements whose kivas
in addition to the six pilaster-sipapu-fireplace-deflector and above-floor
ventilator combination of Mancos Phase kivas, have the deep south
banquette as an established feature. Here, then, in O'Bryan's
post-1050 McElmo Phase is the fully developed Mesa Verde kiva of
Kidder's definition, the one with the deep south banquette. O'Bryan
found no pure McElmo site but noted that McElmo Black-on-white
pottery sometimes occurs on Mancos ruins and even on those of
post-McElmo times.

At their Site 16, also on Mesa Verde, Lancaster and Pinkley
(1954, p. 70) noted that "90 percent of the pottery . . . is assignable
to the P. II period, or the Mancos Mesa phase." Reed (1958)
recognized both Mancos and McElmo among Chaco-like sherds at 4
late P. III, or Mesa Verde, sites he excavated in Mancos Canyon but
regarded the McElmo as merely an improved Mancos. "Generally,"
he wrote (ibid., p. 83) "Mancos Black-on-white has been called
`Chaco' pottery or thought of as closely related to Chaco pottery" and,
again, as though clarifying Morris, "The so-called non-Chaco pottery
of the Chaco period on the La Plata is clearly Mancos Black-on-white
decorated with solid elements, lines and dots, and parallel stripes; the
so-called Chaco-like is hachure-style Mancos" (ibid., p. 97).

When Brew (1946, p. 285) found Mancos Black-on-white and
McElmo Black-on-white intermixed in household waste on Alkali
Ridge he listed the former as P. II and the latter as P. III but added
"the Mancos . . . had begun to show Mesa Verde features. The

Mesa Verde was for the most part of the kind that could be called
McElmo." Under the circumstances Brew took a second look at the
McElmo and decided on the spot "to call it early Mesa Verde."

Early Mesa Verde, or McElmo, Black-on-white is a conspicuous
variety at Chaco Canyon ruins, large and small. It was abundant in
late deposits at Pueblo Bonito and upcanyon; it was preponderant at
Pueblo del Arroyo (Judd, 1959, p. 175; Vivian, 1959, p. 26). Its
off-color white slip, its rounded or flattened and tick-marked rim, its
black organic paint, and its near-Mesa Verde designs separate it from
other local types. It was a late arrival at Pueblo Bonito since, in 12
feet of West Court rubbish, Roberts and Amsden recovered no sherd
of it below the upper 4 feet. Hence McElmo Black-on-white serves
as an index to the comparative age of household sweepings wherever
found in the valley.

At Łeyit Kin and Bc 50-51, small-house sites opposite Pueblo
Bonito, the presence of Mancos Black-on-white and McElmo Blackon-white
proved puzzling to Brand, Kluckhohn, Dutton, and their
colleagues from the University of New Mexico because, as I read
their evidence (Brand, et al., 1937; Dutton, 1938; Kluckhohn and
Reiter, 1939), all were too intent upon a greater antiquity. Casual
sherd samples I collected in 1920 at half a dozen small sites on the
south side of the canyon between The Gap and Wirito's Rincon
(U.S.N.M. Nos. 315841-867), and perhaps including Bc 50-51 and
Łeyit Kin, contained such a large proportion with Mesa Verde-like
designs I classified them at the time as P. III and thus contemporaneous
more or less with the major Chaco ruins (Judd, 1921,
p. 102).

Based on this 1920 judgment, our Pueblo Bonito stratigraphy,
and excavation data since published, Łeyit Kin and Bc 50-51 appear
to me no more than P. III offshoots from Pueblo Bonito or Chettro
Kettle. Use of cottonwood and pinyon vigas (Kluckhohn and Reiter,
1939, p. 33) was a P. II trait at Old Bonito; "keyhole" kivas with
high masonry pilasters and above-floor ventilators echo the Mesa
Verde country. Only one kiva, No. 4 at Bc 51, had a subfloor
ventilating system; all pottery types reported, irrespective of name,
are varieties represented in the 12-foot-deep rubbish in the West
Court at Pueblo Bonito. The preponderance of McElmo Black-onwhite
at Bc 50-51 together with rude masonry when tabular sandstone
was readily accessible, adult burials in rooms, and use of potsherds
as wall chinking combine to suggest a late P. III, Mesa Verde-like
occupancy. Seven timbers from Łeyit Kin were all felled in A.D.
1039 (Dutton, 1938, p. 23). That an underlying pit-house was encountered

during excavation of Bc 50 is quite within reason for a
typical P. I shelter lies at the base of a near-by slope and P. I or
older peoples were long resident in Chaco Canyon (Judd, 1924b;
Roberts, 1929; Bryan, 1954).

The association of P. II and P. III cultural traits, including
kiva fixtures, is apparent at other sites, large and small, throughout
the Chaco area. Still others, as Kidder (1924, p. 57) anticipated,
may represent an earlier or a later horizon. There are the ruins
Amsden examined south of Pueblo Bonito, and there is the one
Roberts partially excavated in 1926 about 10 miles to the east (Judd,
1927a, p. 166). This latter contained so many adult burials and so
many pieces of late Mesa Verde pottery (U.S.N.M. Nos. 334123-154)
is was dubbed at the time "the Mesa Verde house."

Under special permits from the Department of the Interior, the
Pueblo Bonito Expedition in 1925 extended its inquiries beyond Chaco
Canyon. Monroe Amsden that year examined 16 small-house ruins in
Kinbiniyol Valley, south of the Chaco (U.S.N.M. Nos. 329803-845)
and the following summer, 1926, Frank H. H. Roberts, Jr., cut two
stratigraphic sections, one 10 feet deep and the other 12, through
village waste at Pueblo Alto, on the cliff north of Pueblo Bonito,
and three similar tests, varying in depth from 3 feet 3 inches to 8 feet
8 inches, at Peñasco Blanco (Judd, 1927a, p. 168).

Amsden's data remain unpublished, but together his 16 small
ruins impress me as being hastily built, briefly occupied refuges
of post-P. II family groups, harried and on the run. Masonry,
for example, is primarily of wall-wide sandstone blocks, relatively
thick, not face-dressed but amply chinked, and with upright slabs
at the base. Ruin 13, a compact unit in one corner of a slab-enclosed
court, includes a kiva without pilasters but with a shallow basal
recess at the south and a deeper banquette above, a square ventilator
opening 2 inches above floor, a wattled deflector banked with adobe,
a masonry-lined fireplace, and a probable sipapu. Ruin 13 potsherds
(U.S.N.M. No. 329823) include Straight-line Hachure but those
with solid lines, stepped triangles, ticked lines, and checkerboard
figures are more numerous.

The stratigraphic data collected by Roberts at Peñasco Blanco
and Pueblo Alto were, with my permission, included in his 1927
doctoral dissertation at Harvard and have since been cited repeatedly
by other investigators. For our present review of Chaco Canyon
history, however, it is important to note that the Pueblo Alto sherds
(U.S.N.M. Nos. 334161-162) evidence construction and abandonment
while Pueblo Bonito was in its prime since Old Bonitian types and

the famed hachured varieties of the Late Bonitians are both generally
missing. At Peñasco Blanco, on the other hand, Roberts's stratigraphy
reveals Transitional and Degenerate-Transitional from bottom to top,
Chaco-San Juan and other late varieties in the upper strata only
(U.S.N.M. Nos. 334166-168). This sherd record, coupled with a
section of first-type, or Old Bonitian, masonry visible on the northwest
side (the only ruin other than Pueblo Bonito where such
masonry is known to occur in Chaco Canyon) suggested to Roberts
that Peñasco Blanco was founded about the same time as Pueblo
Bonito but may have been abandoned a bit earlier.

Potsherds we gathered in 1920 and 1925 from the surface at
Chettro Kettle, Hungo Pavie, Una Vida, Weje-gi, and Pueblo Pintado
likewise include relatively few Transitional and associated Old
Bonitian fragments in proportion to later varieties such as the three
hachured types, our organic-paint Chaco-San Juan or McElmo
Black-on-white, and Corrugated-coil Culinary. This preponderance
of late over early varieties of pottery suggests to me an outward movement
from Pueblo Bonito—an outward movement which other students
will dispute and which, admittedly, is not fully substantiated by
our too-short list of constructional dates.

The number and range of tree-ring dates from major Chaco Canyon
ruins, originally reported for the Pueblo Bonito Expeditions by
Douglass (1929, 1935), have recently been reviewed by Smiley
(1951) and Bannister (1959) and are listed herewith, from Peñasco
Blanco eastward to Pueblo Pintado, the out-of-canyon sites being
grouped at the end:

Ruin	Number	Range of cutting dates
Peñasco Blanco	(18)	898-1087
Ruin 9 (Casa Chiquita)	(1)	-1060
Ruin 8 (Kin Kletso)	(17)	1059-1178
Pueblo del Arroyo	(35)	1025-1117
Pueblo Bonito	(71)	828-1126
Chettro Kettle	(351)	911-1116
Hungo Pavie	(14)	942-1077
Una Vida	(8)	847-1048
Weje-gi	(1)	-1027
Pueblo Pintado	(2)	-1060
Pueblo Alto (N. cliff)	(0)
Sin-kle-sin (S. cliff)	(2)	-1111
Kinklizhin (Black House)	(1)	-1084
Kinbiniyol	(9)	941-1124
Kinya-a (Pueblo Viejo)	(6)	1097-1106

Tree-ring dates merely suggest the period during which construction
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 collected
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 advancing
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 simultaneously
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. Malnutrition
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.

To judge solely from this Pueblo Bonito sequence, upcanyon
masonry is all late. If my presumed eastward movement were spurred
in any degree by enemy peoples, Weje-gi displays the only evidence—
a row of cliffside portholes. Pueblo Pintado, easternmost of the major
Chaco ruins and a prominent landmark from every direction, stands
astride the Continental Divide.

Once the Divide had been attained which path was taken by bearers
of the Chaco Culture? I do not know. Dispersal was by clan or
family groups, the Late Bonitians first and the Old Bonitians sometime
after. Nowhere is there evidence of mass migration. The two
peoples did not necessarily follow the same trail but both left Chaco
Canyon. Small pure Chaco sites are reported along the Continental
Divide, southward from Pueblo Pintado and West of Mount Taylor.
Reed (1950, p. 92) postulates a population shift eastward to the
upper Rio Grande but elsewhere (1955, p. 179) recognizes among
potsherds collected in the Zuñi country "true Chaco Black-on-white of
the twelfth century."

A twelfth century migration southward from the Chaco country
seems entirely reasonable. The latest known growth-ring from
Pueblo Bonito is A.D. 1126; only one later Chaco date has been
reported, A.D. 1178 from Ruin 8 (Kin Kletso) a half-mile west of
Pueblo Bonito (Bannister, 1960, p. 20). All Late Bonitian rooms we
explored had been vacated and stripped of their furnishings while
the Old Bonitians continued in residence, storing their autumn
harvests and, contrary to their cultural heritage, burying at least
some of their dead in unused groundfloor rooms.

The small clustered rooms of Hopi towns have always seemed
to me a reflection of those in Old Bonito just as the large, highceilinged
rooms of Acoma and Zuñi have seemed to echo those of Late
Bonito. This is only a personal impression, to be sure, but Chaco
Canyon influences are stronger in south central New Mexico than in
any other area personally known to me. And there remains the
intriguing fact that the Zuñi, culturally Puebloan, are an isolated
linguistic group.

The paired kivas Hodge (1923) excavated back of Hawikuh are
pre-Zuñi and follow the Chaco tradition with their subfloor ventilators
and sunken vaults west of the fireplace. Ruins underlying Ketchipauan,
one of the Seven Cities of Cibola, are of excellent masonry
and the equal of that at the paired kivas near Hawikuh.

In a letter of August 18, 1921, addressed to the first symposium
held at the National Geographic Society's Pueblo Bonito camp, N. C.

Nelson recalled his observations at Acoma pueblo where house construction
and orientation reminded him of ruins in Chaco Canyon
although he saw no comparable affiliations in local pottery.

At Kiatuthlanna (1931), the Village of the Great Kivas (1932),
and at Whitewater (1939, 1940), Roberts laid bare a cultural sequence
extending from BM. III and P. I pit-houses to the terraced buildings
of Pueblo III. Echoes from the Chaco were everywhere present and
so were traits from the Mesa Verde country. With the sipapu an
almost constant feature and base slabs overlain by coursed masonry
occurring more frequently than is customary for their kind, the
Whitewater pit-houses may represent a local architectural advance
over those elsewhere or they may reflect usurpation of existing dwellings
by later immigrants. Pit-house Number 2, for example, provided
a tree-ring date of A.D. 814 while a room in Unit 3, a P. II building,
gave one 200 years later, A.D. 1014, obviously late for a P. II structure.
Summarizing his researches in this area, Roberts wrote (1939,
p. 263) "the ruins . . . represent a peripheral lag in the Chaco
pattern and, despite many recent expressions of opinion to the contrary,
the flow of influence was from the Chaco . . . and not the
reverse."

The Village of the Great Kivas on the Zuñi Reservation with its late
Chaco masonry and pottery (Roberts, 1932); the two pre-Zuñi kivas
near Hawikuh (Hodge, 1923); the typically Chaco black-on-white
pottery from small-house sites south of Fort Defiance, Ariz. (Kidder,
1924, p. 56); the two earth-walled kivas at Site LA 2505 about 20
miles north of Gallup, N. Mex., one (B) with a deep south banquette,
sipapu, above-floor ventilator, and tree-ring dates of A.D. 1020 and
1047 (Smiley, 1951, p. 26), and the other (A) with a lateral ventilator
sealed and replaced by one of the subfloor variety (Bullard and
Cassidy, 1956); the late Chaco masonry, Chaco-like pottery, and a
Great Kiva in Manuelito Wash, south of Gallup (Reed, 1944, p. 167;
Judd, 1954, p. 34), and Seltzer's comparative data (1944, p. 17) on
Old Zuñi and Pueblo Bonito skulls, all offer strong support for the
theory of a southward trek from Chaco Canyon in the twelfth
century or thereabout.

Gladwin (1945), Martin (1936), and O'Bryan (1950) are among
those who see the Chaco Culture rising from BM. III and P. I pithouses
of the Little Colorado-Puerco drainage and spreading thence
northward through increasingly larger settlements to its demise in
Chaco Canyon. Roberts and the present writer see distribution in the

opposite direction, from north to south, but neither is yet prepared
to put a finger on the place of origin.

At Pueblo Bonito we have the distinct P. II culture of Old Bonito
and the better known P. III culture of the Late Bonitians. Both were
born somewhere among the sage-covered mesas and valleys of southeastern
Utah and southwestern Colorado. There, among those valleys
and mesas, the whole panorama of Pueblo architectural development
lies exposed to view—a development that extends from single, earthwalled
pit-houses to the wide-curving post-and-mud surface communities
of P. I, to the wall-width masonry and crescentic grouping of
P. II dwellings and storerooms and, finally, to the many-roomed,
multiple-storied towns of Pueblo III. Somewhere in that far-reaching
scene, and most likely where Pueblo II flourished, eventually
will be found the cross-road from which the so-called Mesa Verde
and the Chaco peoples took their separate ways.

The masonry-lined subfloor vault of Chaco kivas, although of
unknown purpose, seems so unusual a feature its origin and development
should be traceable. But nowhere among published descriptions
do I find anything even remotely comparable except the oval depressions,
filled and floored over, reported by Roberts (1939, p. 106) in
P. I Structure 12 at Whitewater, Arizona, and by O'Bryan (1950,
p. 34) in a P. II kiva at Site 102, Mesa Verde National Park, Colo.,
150 miles distant.

At some as yet undetermined point in Pueblo prehistory, clan
ritualists replaced the four traditional roof-supporting posts with
masonry columns and later replaced these with low-log-enclosed
pilasters. At some still unidentified stopping place they introduced
a new, subfloor type of ventilator, eliminating the deflector. The
one Morris (1939, p. 53) describes in a P. II kiva under Building I,
Site 39, is the earliest of which I am aware but a companion kiva,
Number 2, was typically Mesa Verde with its 6 masonry pilasters, a
deep south banquette, and a lateral ventilating system. I know of
no horizontal, log-enclosed pilaster earlier than those in the bowlshaped
P. II kivas at Pueblo Bonito.

Lowry Ruin, the West Pueblo at Aztec, Solomon's Ruin near
Bloomfield, N. Mex., and the short-lived structure on Chimney
Rock Mesa near Pagosa Springs, Colo. (Jeancon, 1922; Roberts,
1922), are among those repeatedly described as probable colonies from
Chaco Canyon. Available tree-ring dates as listed by Smiley (1951)
lend credence to this theory of colonization since a majority—49 from
Aztec, A.D. 1110-1125; 9 from Lowry, 987-1086; 3 from Solomon's

Ruin, 1086-1089—lies in the last third of dated architecture at Pueblo
Bonito. But the subject is not so easily dismissed.

The East Kiva on Chimney Rock, which seems so isolated and
alone, is undeniably Chaco-like in its lack of a sipapu, its low logenclosed
pilasters, its west-side vault, and a subfloor ventilating system
that was rebuilt to the original plan when the floor was raised.
These Chaco resemblances invite further exploration, but at the time
of his initial visit Roberts (1922, p. 12) recorded his then opinion
that Chimney Rock pottery looked older than that of Chaco Canyon.
If he is correct in this early impression then the associated Chaco-like
masonry must be older and Chimney Rock stands not as a colony from
Chaco Canyon but as a possible way station on a path southward.

"The Chaco-like remains north of the San Juan, both architectural
and ceramic," wrote Earl Morris (1939, p. 204), "are so widespread
and so numerous that I consider it untenable to view them wholly as
an extension of or a backwash from, the Chaco Canyon center. . . .
The most Chaco-like of the vessels from the north country, which
seem so significant when viewed singly or selectively grouped, become
far less so when viewed as the minor component that they are of the
totality of wares among which they occur."

Kidder obviously had the same intangible evidence in mind when
he observed that Chaco-like vessels from Montezuma Valley and
McElmo Canyon, target of commercial and amateur collectors for
half a century, "are seldom of the most pronounced Chaco types; they
give one the impression of being either the product of a peripheral
development affected by Chaco influence, or of an earlier and less
specialized stage of the Chaco culture" (Kidder, 1924, p. 56). They
may, he added, "indicate a northwestern spread or a northwestern
origin" of that culture. Anna Shepard may have seen a like probability
when she hinted (1939, p. 285) a common source in early P. III
times or previously for the mineral-paint Chaco and the carbon-paint
Mesa Verde wares.

Morris doubtless would have regarded Chimney Rock pottery as
"more Chacoesque than Chaco." To him the many small ruins
throughout the San Juan and Animas valleys in which Chaco-like
pottery predominates might be earlier, contemporary with, or even
later than Chaco-like Aztec pueblo (Morris, 1928, p. 418). He does
not so imply but some one of these small ruins may have spawned the
unique ideas in architecture and in pottery ornamentation that brought
about the Pueblo III conquest of Chaco Canyon.

In pursuing our investigations for the National Geographic Society

we failed to identify all the distinctive qualities that have set the
Chaco Culture apart, but we did discover a great deal previously
unknown about Pueblo Bonito. We learned that it is the architectural
product of two unrelated peoples; that the first of these had been
in residence long enough for 5 or 6 feet of blown sand to pile up
against their homes before the second group arrived and built upon
that sand. Source of the domestic water supply at Pueblo Bonito
remains a mystery, but we turn with increasing favor toward the
Navaho tradition that water could be had with shallow digging almost
anywhere in the valley before erosion of the 1850 arroyo. The great
natural cistern on the north cliff overlooking Pueblo Bonito was of
limited capacity, even if it existed in A.D. 1000.

We learned that the forests which furnished roofing timbers for
Pueblo Bonito flourished when rainfall was more abundant than it is
today; that slow-flowing floodwaters following summer rains had
spread widely across the valley floor annually depositing enough black
alkali to lessen the productivity of village fields before a 12th-century
arroyo lowered the water table beyond reach of surface vegetation.

We learned that each of three Late Bonitian additions to the
original settlement had forced the abandonment and destruction of
dwellings previously built; that plans for a fourth and more extensive
addition were left incomplete and a substitute adopted. We learned
that this substitute was itself abandoned when the Late Bonitians
migrated, leaving their Pueblo II co-residents behind in sole possession
of the compound pueblo. That these original settlers were
last to depart is clear from the foodstuffs, the household utensils,
and the ceremonial paraphernalia they left in their brush-roofed
houses.

Reduction in arable lands, a consequence of reduced rainfall or
erosion, seems a most likely cause for desertion of Chaco Canyon by
the Bonitians. The Great Drought of 1276-1299 occurred 100 years
too late to have been influential, but that of 1090-1101, perhaps an
incentive for Bryan's buried arroyo, could have spurred the outgoing.

In the chapters which follow I shall seek to present Pueblo Bonito
as we now know it, from the original P. II settlement to the last of
the three additions planned and executed by the Late Bonitians.

[1]

Mammalian remains and plant products recovered from Bonitian rubbish
during the Society's investigations are listed in Judd, 1954.

University of Virginia Library

THE ARCHITECTURE OF PUEBLO BONITO

(With 81 Plates)

I. INTRODUCTION AND CONCLUSIONS