#### Population Estimates

*by Kristin A. Kuckelman*

^{1}

Estimating the population size of a hamlet or village is important for understanding subsistence and sociopolitical
organization, as well as regional population trends. Arriving at an accurate estimate of population, however, is tricky.
Researchers have developed a number of methods for estimating population
(Cook 1972*1; Hassan 1981*1), with varying success. These
methods include estimating on the basis of floor area (LeBlanc 1971*1; Naroll 1962*1), number of households (Lightfoot 1994*1), number of rooms
(Hill 1970*1), number of kivas, number of artifacts (Cook 1972*1:11–12; Hassan 1981*1:78–79), amount of food refuse
(Cook 1972*1), area of roomblock rubble on the modern ground
surface (Adler 1990*5; Schlanger
1987*1), hearth size (Ciolek-Torrello and Reid
1974*1), site size (Hack 1942*1), and number of
burials or bones (Cook 1972*1). The success of these
methods depends on many factors, and how well a specific method works for a
particular site depends on the kind of site it is and on the types of data
that were collected. The methods considered most useful for estimating the
population of Castle Rock Pueblo include calculations based on total floor
area or roofed area, the number of households, the number of rooms, and the
quantity of
human skeletal remains.^{1}

**Population Based on Area**

^{2}

Studies in which population is estimated on the basis of architectural measures emphasize that usually not all structures in
Puebloan sites were in use at one time. This requires a downward adjustment in the population estimate to allow for the
abandoned structures. Castle Rock Pueblo, however, was occupied for a relatively short time, and it appears that only a few
structures had fallen into disuse before the habitation of the village ended, sometime after A.D. 1274. Consequently, no
adjustment was made to the following estimates to allow for abandoned rooms.

^{3}

On the basis of his study of floor areas in 18 societies, Naroll (1962*1) suggested a formula of 10 m^{2} (108 ft^{2}) of floor
area per person to estimate population. To use this well-known formula for Castle Rock Pueblo, I first summed the floor
areas of all known structures, for a total of 396 m^{2} (4,261 ft^{2}). Dividing by 10 m^{2} gives a population estimate of 39.6, or 40
people. This seems to be too few people to have constructed and occupied all of the structures known to have been present
in the village. It is probably safe to assume, however, that we did not find all structures during our excavations. It is
possible that a similar roomblock or at least a similar amount of floor space once existed in each residence cluster. Using
the one mostly excavated roomblock (Roomblock 103) as a model, I projected the total floor area that would have been
present in the village if all roomblocks were the same size. Roomblock 103 encompassed 31 m^{2} (333 ft^{2}) of floor area. If
each of the 15 kivas of ordinary size was originally paired with 31 m^{2} of surface rooms, then the total floor area of the
village would have been 465 m^{2} (5,003 ft^{2}) of surface room area plus 188 m^{2} (2,023 ft^{2}) of kiva floor area. This would boost
the total floor area for the village to 653 m^{2} (7,026 ft^{2}). Using Naroll's formula of 10 m^{2} per person, I estimate a population
of 65 people, which seems reasonable. But it is difficult to believe that we overlooked 257 m^{2} (2,765 ft^{2}) of surface rooms,
and the use of Naroll's formula has resulted in seemingly low population estimates for researchers in the past (Hassan
1981*1:73; Hill 1970*1:76–77; Kuckelman 1977*1:82).

^{4}

Dohm's (1990*1:Table 3) data on 22 historic-period Pueblo villages indicate an average of about 17 m^{2} of total roofed
area per person. Total known roofed area at Castle Rock (which, unlike floor area, includes benches and southern recesses
of kivas) is 475 m^{2} (5,111 ft^{2}). Use of Dohm's formula gives a population estimate of 30 people for the village, which is
even lower than the estimate derived using Naroll's formula. Using Roomblock 103 as the model roomblock for the site, as
I did in applying Naroll's formula, I estimate the total projected roofed area of the village at 729 m^{2} (7,844 ft^{2}). Dividing
this by 17 m^{2} gives a population estimate of 43 people. This would mean an average of about three people per kiva, which
still seems too low. To check this impression, I used the same formula on the area contained in the 103 residence cluster by
itself (roomblock and kiva). In other words, I divided 50.3 m^{2} (541 ft^{2}) by 17 m^{2} (183 ft^{2}), which resulted in a population
estimate of three people for that residence cluster. This is too few people to have constructed and used a kiva and six
rooms, including four front rooms with hearths. I conclude that historic Pueblo households contain much more space per
person than did Castle Rock Pueblo residence clusters.

^{5}

Calculating the population of Broken K Pueblo in Arizona, Hill (1970*1) used a variety of methods to arrive at a formula
of 4.55 m^{2} (49 ft^{2}) of area per person. Applying Hill's formula to the floor area actually found at Castle Rock Pueblo (396
m^{2}, or 4,261 ft^{2}) yields a population estimate of 87 people. With 15 residence clusters (Structure 105 is believed to have
been a communal structure and might not have been part of a residence cluster), Castle Rock Pueblo would have had an
average of 5.8 people in each cluster, which is probably not unreasonable.

**Population Based on Number of Households**

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Number of households can also be used to estimate population. Lightfoot (1994*1:148) concluded, on the basis of several
cross-cultural studies of household size, that one could expect households in ancient pueblos to have ranged between two
and 12 people and to have averaged between five and eight. The problem at Castle Rock is the same problem Lightfoot
(1994*1:148–149) faced with the Pueblo I Duckfoot site, which was figuring out which physical remains represented a
"household." Following Kroeber (1917*1:124), Beaglehole (1935*1:42) defined a household for modern Hopi
villages as the house unit in which several people live around one hearth.
This definition has been widely used by archaeologists in interpreting
ancient pueblos (Cook 1972*1:16; Hill
1970*1:76; Kane 1986*1). If each of the four front rooms
with hearths in Roomblock 103 at Castle Rock Pueblo represents a separate
household, then this residence cluster housed between eight and 48 people.
On the other hand, if the entire 103 residence cluster (kiva and rooms)
represents one household, then the estimated number of residents falls to
between two and 12 people. On the basis of Cook's (1972*1:Table 1)
cross-cultural information on the floor areas of houses that probably each
contained a single nuclear family, it appears that the
front-and-back pairs of rooms in Roomblock 103 (for example, Structures 121
and 122) are very small to have housed separate nuclear-family households.
Given the small sizes of the rooms, then, I propose that the 103 residence
cluster consisted of one large household rather than four households. For
the site as a whole, I believe that each of the 15 small kivas represents
one household. Using the average household size of between five and eight
people cited
above, this results in a population estimate for the entire village of between 75 and 120 people.

^{7}

In his calculations of numbers of people in households, Cook (1972*1:16) used a formula of 25 ft^{2} (2.3 m^{2}) of space per
person for the first six persons in a household and allowed 100 ft^{2} (9.29 m^{2}) of space for each additional person. For
Roomblock 103, this formula gives an estimate of eight people, or 10 people if the kiva is counted as domestic space. If
eight to 10 people occupied each of the 15 known residence clusters at Castle Rock, then the village contained 120 to 150
people.

**Population Based on Number of Rooms**

^{8}

Population estimates can also be based on the number of rooms in a village. In estimating the population of Broken K
Pueblo, Hill (1970*1:75) used information from modern Hopi and Zuni pueblos to arrive at a formula of 2.8 people per
room, based on an average room size of 9 m^{2} (96.8 ft^{2}). The average size of rooms that could be accurately measured at
Castle Rock Pueblo was 9.15 m^{2}, so this formula should be usable for Castle Rock. At least 40 rooms are known to have
been present at Castle Rock. If the population equaled 2.8 people per room, then 112 people lived in the village.

**Population Based on Human Bones**

^{9}

The final method used to estimate the population of Castle Rock Pueblo was to calculate the number of people represented
by the human bones found during excavations. It seems safe to assume that some people died during the 20-year occupation
of the village, although no formal burials were encountered during the
five seasons of excavation there. How many people died during the
occupation of Castle Rock Pueblo? Schlanger (1992*1:15)
estimated, on the basis of analyses of Southwestern burial populations,
that four to six people out of every 100 would have died each year. The
chronology for Castle Rock is not precise enough to enable calculation of
the size of the village year by year, but if its population averaged 50
people for the last 10 years of occupation, then at least 20 to 30 Castle
Rock inhabitants must have died during the occupation of the village. It
is possible that, by chance, no test pits were excavated where any formal
burials were located, or that all the dead were buried in a specific
location that is as yet undiscovered (such as on the nearby floodplain of
McElmo Creek). It is also possible, considering the widespread
recreational digging that occurred in the area historically,
that some burials were removed in historic times.

^{10}

Although no formal burials were found, human bones were discovered at the site, all in locations and conditions indicating
that these people died in the final days of occupation (see also "The Final Days of Castle Rock Pueblo"). The skeletal remains
of some individuals were relatively complete and articulated, but the remains of
most were disarticulated. The number of people
represented by these remains must therefore be estimated. I estimate that
at least 43 people died during the final days of the occupation. There is
no direct evidence to indicate that all of the dead were residents of
Castle Rock, but it can probably be assumed that the victorious attackers
would not have left their dead in an enemy village. Various researchers
have developed methods for projecting the number of inhabitants of a site
on the basis of the number of human bones recovered, but many problems have
arisen with these methods (see Cook 1972*1:4–7).
Therefore I do not attempt to estimate the population of Castle Rock Pueblo
on the basis of the number of human bones. At least 41 people are
represented by the human remains documented at Castle Rock, and this number
is offered as a minimum population for the
village when the occupation ended.

**Summary**

^{11}

The population of Castle Rock Pueblo was estimated using various methods and formulas. Estimates based on floor area
and total roofed area were as low as 43 people and as high as 87. Estimates based on the number of households present at
the site tended to be higher—75 to 150 people. The number of rooms thought to have been in the village was used to
estimate a population of 112 inhabitants. The human bones indicate that at least 41 people died in the village during the
violent events that effectively ended the occupation.

^{12}

Because above-ground rooms were difficult to find during the excavations (see "Architecture") and more emphasis was
placed on finding kivas than on finding rooms during testing, I believe the
most accurate population estimate is that based on the number of households
in the village. The number of households is thought to be indicated by the
number of kivas. Thus, I propose that the estimate of 75 to 150 people is
the most accurate, although I favor the low end of this range
because of the small number of rooms found.

^{1} Analysis results for the human skeletal remains at Castle Rock Pueblo are not included in this publication. The complexities of the analysis and subsequent interpretations require treatment that is beyond the scope of this publication. An article is currently being written for submission to a professional journal.

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