Prehistoric roads play an important role in defining both the extent and cultural features of the Chaco Anasazi, a seemingly centralized tradition that emerged in the northern Southwest between A.D. 900 and 1150. Characterized by monumental Great Houses and subterranean Great Kivas, the so-called "Chaco phenomenon" was focused on Chaco Canyon, where a concentration of these architectural features has been identified. This is also the location from which a number of prehistoric roads appear to emanate and extend over northwestern New Mexico (Figure 1). Because projections of these roads seem to connect surrounding areas of Anasazi habitation with Chaco Canyon, scholars often see them as having served an economic function for reducing the costs of moving food, pottery, construction materials, prestige goods, and people between far-flung Chacoan communities(e.g., Betancourt et al. 1986; Ebert and Hitchcock 1980; Judge 1984; Mathien 1991; Powers 1984; Wilcox 1993; Windes 1991).


Figure 1: This map illustrates the spatial extent of the prehistoric Chaco Anasazi and one version of the road network they constructed (Powers 1984:54). The study area for this project is centered on Lobo Mesa south of Chaco Canyon, including the Kin Ya'a, Casamero, and Coolidge communities.


More recently, however, archaeologists have begun to propose other explanations for the Chacoan roads. These new models are based on ceramic evidence that the Chaco Anasazi may not have been as well-integrated as was previously assumed (Sebastian 1992; Toll 1991). A reexamination of the roads has also revealed that many roads may not have actually connected communities with one another or even with Chaco Canyon (Nials et al. 1987; Roney 1992). Similarly, the identification of road sections in areas far beyond the traditionally defined borders of the Chaco system has led to a reevaluation of the degree of integration that these features might represent (Roney 1992; Vivian 1996:9-10). This has resulted in alternative explanations that see roads as having served religious (Fowler et al. 1987; Sofaer et al. 1989), integrative (Roney 1992), and perhaps political functions (Kantner 1996) on a local level.

This study hopes to contribute to this debate by providing a case study from a relatively small area in the southern San Juan Basin approximately 50 km. from Chaco Canyon. Numerous roads have been identified in this area (e.g., Nials et al. 1987), but most are only short fragments that may or may not have once been longer. Through the use of Geographic Information System technology, this study evaluates the possible functions of these fragments by modeling the paths that roads should have taken given the three general approaches to explaining Chaco road function: economic, religious, and integrative.

The study area of approximately 2500 km2 is centered on Hosta Butte, a prominent geological feature located between Grants and Gallup, New Mexico (Figure 2). Previous investigations in this area have identified over 1,600 Anasazi sites and more than 20 sections of road of which all but one are closely associated with prehistoric communities (Kantner 1996; Nials et al. 1987). This information was assembled in a Geographic Information System database (GIS) using ESRI's Arc/Info software. Contextual information on elevation, water, and land use have been added to the GIS, and this is currently being augmented with additional data on soil characteristics.

Figure 2: The study area consists of 13 communities located on the north and south sides of Lobo Mesa. The dotted lines represent the network of cost-paths that minimize travel time between the communities. The red dot in the center of Lobo Mesa is Hosta Butte, a prominent feature visible over long distances. The grayscale background indicates elevation, with values ranging from 1968 m. (black) to 2674 m. (white).


The Anasazi sites in the study area are concentrated on the northern and southern sides of a large plateau known as Lobo Mesa. The majority of Anasazi occupation occurs during Pueblo II (A.D. 900 -1100), with most habitation sites found in about a dozen communities. Great Houses and Great Kivas similar to those found in Chaco Canyon are found in each community, which, together with the road segments associated with several communities, demonstrate that the area can be defined as part of the Chaco Anasazi system (Kantner 1996).

In order to evaluate the four general models of Chaco road function, a cost surface was generated for the entire study area using the GIS. First, Digital Elevation Models (DEMs) available through the U.S. Geological Service were acquired. Each DEM consists of a grid of points that record elevation at 30 m. or 100 m. resolutions. Based on these elevation data, a new grid of points covering the study area was generated in Arc/Info using the following formula:

T = D/(6 exp ( -3.5 * abs(S + 0.05)))

T = time to cross each cell of the DEM
D = distance across each cell
S = slope

This formula, known as the "hiking function," was developed by geographer Waldo Tobler (1993:4), and has been successfully evaluated using both archaeological and ethnographic data (Gorenflo and Bell 1991; Aldenderfer in press). Application of this formula produced a cost-surface measuring the amount of time it would take to cross each cell.

The study initially tested DEMs with both 30 m. and 100 m. resolutions. The results clearly demonstrated that cost-surface analyses are quite sensitive to data quality. Tests comparing the two resolutions showed that the use of 100 m. DEMs resulted in a cost-surface that did not compare well with real-world topography (Figure 3). For this reason, 30 m. DEMs were used in the final analyses.

Figure 3: Digital Elevation Models at 100 m. resolutions resulted in cost-paths (indicated by the green lines) that did not adequately model real-world topography. In contrast, DEMs with a 30 m. resolution (indicated by the red lines) produced superior results.

The resulting cost-surface provided the basis for evaluating the models of road function. Based on expectations for each model, cost-paths could be generated and compared with the actual road segments. For example, a common interpretation of the roads is that they facilitated economic exchange and foot travel between Chacoan communities (e.g., Kane 1993; Wilcox 1993; Windes 1991). Using the cost-surface, the GIS could choose the paths between the communities that minimized travel time. The resulting cost-path network (Figure 2) could then be compared with the prehistoric road segments to see how closely the modeled paths fit the actual routes of the roads. The specific expectations and evaluations of each of the three models, as well as some unexpected patterns revealed in this study, are discussed in the remaining panels.

Since the 1970s, archaeologists investigating the Chaco Anasazi have tended to see the prehistoric roads in the northern Southwest as having served an economic function (Ebert and Hitchock 1980; Judge 1984; Kane 1993; Mathien 1991; Powers 1984; Wilcox 1993; Windes 1991). These theories are stimulated by the fact that the roads appear to begin in Chaco Canyon and extend over the San Juan Basin. Economic explanations are often rooted in general theories of Chaco Anasazi development that see the system evolving in order to contend with spatially heterogenous resource availability. For example, some scholars argue that Chaco Canyon served as a central point for redistributing commodities from areas of temporarily high production to those communities experiencing subsistence stress (e.g., Judge 1984; Powers et al. 1983; Tainter and Plog 1994). According to this view, roads expedited transportation across the Chaco system. This conclusion has provided the foundation for a variety of studies employing geographic models to reconstruct the economic and political structure of the Chaco Anasazi (e.g., Ebert and Hitchcock 1980; Schelberg 1982; Wilcox 1993; Winter 1980).

Recent investigations have challenged economic explanations for the road system. Much of this criticism is based on ground surveys that have attempted to verify the presence and antiquity of roads identified through air reconnaissance (Kincaid 1983; Nials et al. 1987). Many of the roads that were once thought to connect communities now appear to have huge gaps in them; in fact, few roads actually extend more than a kilometer or two beyond their point of origin (Roney 1992). However, in many cases it is also clear that natural forces such as erosion or alluviation could have removed or buried many prehistoric road fragments.

For this study, the general economic model of road function was evaluated by determining how closely the road segments followed cost-paths between communities. The results were fairly unequivocal: virtually none of the road segments in the study area came even close to aligning with idealized cost-paths. Figure 4 illustrates this quite clearly. Dotted lines represent cost-paths between the community of Muddy Water and every other community in the study area. The prehistoric road does not align with any of these projected routes, suggesting that the road was not constructed to facilitate economic interaction with nearby communities. The other illustrations on this poster demonstrate similar patterns.

Figure 4: The road segments extending from the Muddy Water community clearly do not align with any of the cost-paths that minimize intercommunity travel time. This roadway may have instead facilitated travel to a spring found at the base of Lobo Mesa. Note the presence of a small Great House southeast of the community that does align with important cost-paths. The grayscale background represents concentric gradients of travel cost away from the community.


There are only two road fragments that may fit the economic model for road function. The first is the famous South Road that originates in Chaco Canyon itself and enters Kin Ya'a (Nials et al. 1987:18-19). This may have served a regional economic role, but because it extends out of the study area its alignment with potential cost-paths could not be evaluated. The second road fragment that may fit the economic model is a small segment of road that is the only one not associated with an Anasazi community, although it is found in a small "hamlet" consisting of a few habitations. This particular fragment aligns with cost-paths between several communities. Whether this is coincidental is difficult to surmise, but the poor fit between all the other road segments and intercommunity cost-paths suggests that it may be.

The evidence from this study demonstrates that Chacoan roads do not fit well with economic explanations based on regional interaction. However, while these roads may not have served to facilitate intercommunity exchange, at least one may have served a more local economic role. A road segment originating in Muddy Water leads to the cliffs at the base of Lobo Mesa where a spring is believed to have once existed. Archaeologists investigating this road identified numerous pot fragments along the road and suggested that these vessels were used to obtain water from the spring (Nials et al. 1987:140-141). Similar local economic functions have also been proposed for other road segments in the San Juan Basin (e.g., Windes 1991:120-122).

In recent years, archaeologists investigating the Chaco Anasazi have tended to focus on religious or cosmographic explanations for the prehistoric roads. These models usually take one of two perspectives. In the first, roads are seen as symbolic representations of Chacoan cosmology (Marshall 1992; Sofaer et al. 1989). Proponents of this perspective focus on the alignment of roads with cardinal directions as well as the axial oppositions that the roads form. Roads of this kind are thought to be completely straight, with no consideration for minimizing either the effort to construct the road or the costs of travelling on them. The most commonly cited example is the North Road, which exhibits a northern alignment and general axial opposition with the South Road (Figure 1) (Lekson 1996; Sofaer et al. 1989).

Other scholars focus on religious explanations that relate the roads to the immediate ritual landscape surrounding the communities from which the roads emanate (Fowler and Stein 1992). Archaeologists espousing this perspective note that almost all roads begin or end at Great Houses or Great Kivas, both which are believed to have served religious functions for the Chaco Anasazi. The identification of some roads connecting non-contemporaneous specialized architecture has led to the concept of "roads through time" that symbolically linked religious features from different time periods (Adler 1994:98-99; Fowler and Stein 1992:116-118; Mahoney et al. 1995).

The first model of religious road function is difficult to evaluate in the absence of a clear idea of the range of possible cosmographical expressions that the Chaco Anasazi might have symbolized. None of the roads in the study area seem to be axial opposites of one another, and none align with any of the cardinal directions. Even the South Road has strayed significantly from due south by the time it enters the community of Kin Ya'a.

In contrast, many of the roads in the study area may have symbolically connected features on the local religious landscape. Several prehistoric road segments clearly link Great Houses to Great Kivas. In a few cases, idealized cost-paths generated between these architectural features correspond with road segments, such as in the community of Andrews (Figure 5). Other completely straight roads connect Great Houses with Great Kivas (e.g., Figure 6).

Figure 5: The roads emanating from Andrews appear to align with cost-paths that meet the expectations of both the integrative and religious models. The segments extending to the west connect with a small concentration of habitations and a great kiva, while the road extending northwest is both on a cost-path and a straight line (yellow) to Hosta Butte, an important feature in the cosmography of contemporary indigenous inhabitants of the region.

Figure 6: One short road segment in Tse Bee Kintsoh connects one of the Great Houses with a nearby Great Kiva. The road segment on the east side of the community seems to align with a Great House, but like a few other cases in the study area, its destination is less clear for it does not fit well with any of the proposed models of road function.


At least two road segments appear to be directed towards Hosta Butte, a prominent geological feature that is visible as far away as Chaco Canyon. The most interesting example of this is the South Road, which originates in Chaco Canyon and passes through Kin Ya'a (Figure 7). This road aligns with a cost-path between Kin Ya'a and Hosta Butte, and it also corresponds well with a straight line connecting these two points. An identical pattern is found for a road segment emanating from the Andrews community (Figure 5). Shrines with offerings have been found on Hosta Butte, which is an important feature in the cosmography of local indigenous groups (Marshall and Sofaer 1988). The road segments suggest that the butte was also an important point on the prehistoric religious landscape.

Figure 7: The famous South Road originates in Chaco Canyon and then passes through Kin Ya'a on a direct path to Hosta Butte, which was likely a prominent point on the religious landscape. Like virtually all of the road segments in the study area, the segments extending from Kin Ya'a do not at all correspond with any of the intercommunity cost-paths.

John Roney (1992) has recently proposed that Chacoan roads functioned to integrate local Anasazi populations over small areas. This model is based on the scarcity of road segments longer than a kilometer or two, as well as on the fact that a Great House or Great Kiva is found at one end of virtually every road segment associated with the Chaco Anasazi. According to Roney (1992:129), this pattern suggests that roads must have served functions similar to these specialized architectural features. By assuming that Great Houses served to integrate local communities, Roney hypothesizes that the roads functioned to direct attention, both symbolically and physically, towards this integrative architecture (Roney 1992:130). In essence, this view sees roads as drawing people from surrounding areas and funneling them towards a particular Great House.

This model receives considerable support from the road segments found in the study area. The majority of roads seem to fit both cost-paths and often direct lines between Great Houses and habitation clusters. In communities such as Coolidge and Blue J, the segments do not extend beyond community boundaries, but instead physically link Great Houses with adjacent areas of relatively dense occupation. In other communities, however, the roads extend beyond the communities to small hamlets located nearby. For example, a road segment in Andrews (Figure 5) corresponds with the cost-path between the community's Great House and a separate cluster of habitations. In a few cases, however, the fit is only suggestive, such as the seemingly isolated road segment in Tse Bee Kintsoh that may or may not have connected one of the Great Houses with a nearby habitation cluster (Figure 6).

Although the pattern of short road segments emanating from Great Houses and terminating in nearby habitation clusters is common in the study area, what this actually signifies is not as clear. In general, scholars investigating the Chaco Anasazi have seen Great Houses and associated architecture as serving to integrate communities, and if true, the roads likely served a similar function as Roney suggests. However, a smaller body of research (Kantner 1996; Sebastian 1992) suggests that Great Houses may have also been arenas of political competition, with local political entrepreneurs maintaining the specialized architecture to impress followers and to upstage potential competitors. From this perspective, short road segments may have been designed not so much to integrate local populations, but rather to augment the influence and prestige of local political leaders. Determining road function in these cases will require archaeological research focused on the role of Great Houses and Great Kivas in Anasazi communities.

As is common in archaeological research, some of the most intriguing patterns identified in this study were not predicted by preexisting models. Of particular interest were patterns revealed through the generation of the cost-paths used to evaluate road function. These unexpected patterns include the close association between so-called "special sites" and intercommunity cost-paths, the appearance of small hamlets at points where several cost-paths crossed, and the placement of small isolated Great Houses on routes between communities.

In the GIS database, the "special sites" category included features identified as either shrines or herraduras. Shrines were defined as small stone circles with diameters of 3 - 5 m. that were associated with Anasazi ceramics (see also Windes 1978; Kincaid et al. 1983:9-20 - 9-23). Some circles were not completely closed, while others surrounded boulders. The clear majority of these features were within a few hundred meters of cost-paths between communities (Figure 8). This pattern was especially prominent north of Lobo Mesa, where the majority of intercommunity cost-paths were associated with shrines (Figure 9). Interestingly, few roads were associated with shrines. Instead, almost all of the herraduras, defined as especially large (6 - 10 m.) masonry or rubble circles (Kincaid et al. 1983:9-14 - 9-16), were located along road segments.

Figure 8: An unexpected pattern identified in this study was the close association between small circular stone "shrines" and the idealized cost-paths between communities. This confirms that a network of intercommunity footpaths did exist, even if they were not formalized as constructed roadways. Instead, the investment in roads and large circular herraduras was apparently reserved for other functions.


Figure 9: Shrines appear in greater numbers between the four communities located north of Lobo Mesa. As in this example of shrines between Kin Ya'a and Muddy Water, they often appear along ridges as if they served as boundaries. Two small, path-related Great Houses located between Dalton Pass, Muddy Water, and Kin Ya'a may have served similar functions.


The network of intercommunity cost-paths (Figure 2) includes a few points where several paths cross. In many of these locations, small clusters of habitations appear (Figure 10). All of these hamlets are considerably smaller than the named communities, and none exhibit specialized architecture such as Great Houses or Great Kivas. All appear late in the Chacoan prehistory of the area, after A.D. 1050, and most occur on Lobo Mesa at elevations that would have made agriculture challenging.

The final unexpected pattern is the association of two isolated Great Houses on prominent cost-paths between Dalton Pass, Muddy Water, and Kin Ya'a (e.g., Figure 4). Unlike most Great Houses, which appear within the heart of communities, these two structures are located some distance from habitation areas, and both are exceptionally small in size. The purpose of these isolated structures has been a mystery.

These unexpected patterns suggest that the cost-paths align closely with the actual routes used for travelling between communities in the study area. At the risk of overinterpreting the data, the shrines may have served as boundaries or stopping places along footpaths between communities (Robertson 1983). However, despite this evidence of intercommunity interaction, apparently it was not formalized by augmenting footpaths and shrines to road and herradura proportions. This pattern provides insight into which spatial networks surrounding Chaco Anasazi communities warranted increased investments in labor and material.

The late appearance of hamlets at important points in the regional network of paths corresponds with the appearance of two path-related Great Houses north of Lobo Mesa. The impression is that the intensity of regional interaction was increasing after A.D. 1050, stimulating the construction of new path-related features. These new patterns warrant further attention, and will undoubtedly provide new insight into the development of Chaco Anasazi communities.

Figure 10: The late appearance of isolated hamlets on Lobo Mesa has been a mystery. However, the fact that they appear in areas where numerous cost-paths in the intercommunity network cross is likely significant. Perhaps they functioned to facilitate regional exchange, or they may have emerged to take advantage of increasing interaction between Chacoan communities. The hamlet above is northeast of Coolidge, while the one below is north of Tse Bee Kintsoh.

The evaluation of the three general models of Chacoan road function suggest that the roads did not function to economically integrate the region. With the notable exception of the South Road between Chaco Canyon and Hosta Butte, none of the road segments in the study area extend more than a kilometer or two, and virtually none fall even close to cost-paths that minimize travel time between communities. In contrast, almost all roads appear to fit more closely with explanations that see the roads as having served localized religious, integrative, and/or political functions (Figure 11).

Figure 11: The road segments in the study area did not facilitate regional economic interaction. The evidence instead suggests that they served more localized religious, integrative, and perhaps political functions. This conclusion indicates that the distribution of prehistoric roads is not necessarily an adequate measure of economic and political integration in the region surrounding Chaco Canyon.

Distinguishing between religious and integrative/political explanations of road function is more difficult. In a few cases, roads fit the expectations of both models. For example, one road segment in Andrews connects the Great House with a nearby cluster of habitations that also includes a Great Kiva (Figure 5), thereby meeting the expectations of both the religious and integrative models. More than likely, an improved model of road function will combine aspects of both complementary interpretations.

Was the GIS necessary to effectively perform this study? Clearly, the various models of road function would have been much more difficult to evaluate without the GIS' ability to generate cost-paths. This is especially true since the roads consisted only of short segments. At the same time, the GIS facilitated the identification of other unexpected patterns that also contribute to the issue of road function and intercommunity interaction in the northern Southwest.

An important issue that needs to be addressed, however, is the best way to evaluate the fit between the idealized cost-paths and the actual road segments. One potential method is through the use of concentric gradients representing movement away from the point of origin. For example, the grayscale backgrounds in Figures 4 and 7 represent gradients away from communities, allowing for a qualitative sensitivity analysis. In Figure 7, the road that appears to extend from Kin Ya'a to Hosta Butte at one point veers away from the idealized cost-path, but the gradient of movement costs away from the community shows that the cost to follow the road was actually very similar to the cost to follow the cost-path. Further research should be invested in methods to more objectively evaluate the fit between modeled paths and the actual prehistoric roads.

Despite the potential for improving the models and methods used in this study, the results do provide a useful evaluation of the function of prehistoric roads used by the Chaco Anasazi. Few roads seem to have been oriented towards regional interaction, with most apparently constructed to serve localized functions. This suggests that the mere presence of roads segments should not serve as a way to determine either the spatial extent of Chaco Canyon's authority or the intensity of large-scale travel and exchange in the region. Perhaps roads were actually a general Anasazi phenomenon that Chaco Canyon manifested at a larger scale through the construction of a few longer roads such as the North and South Roads. Meanwhile, the majority of communities in the northern Southwest continued to construct short roadways for their own purposes.

Adler, Michael

1994 Population aggregation and the Anasazi social landscape: A view from the Four Corners, in The Ancient Southwestern Community, edited by W. H. Wills and R. D. Leonard, pp. 85-102. University of New Mexico Press, Albuquerque.

Aldenderfer, Mark

in press Montane Foragers: Asana and the South-Central Andean Archaic. University of Iowa Press: Iowa City (expected April 1997).

Betancourt, J. L., J. S. Dean, and H. M. Hull

1986 Prehistoric long-distance transport of construction beams, Chaco Canyon, New Mexico. American Antiquity 51(2):370-375.

Ebert, J. I., and R. K. Hitchcock

1980 Locational modeling in the analysis of the prehistoric roadway system at and around Chaco Canyon, New Mexico, in Cultural Resource Remote Sensing, edited by T. R. Lyons and F. J. Mathien, pp. 167-207. National Park Service, Washington, D.C.

Fowler, Andrew P. And John R. Stein

1992 The Anasazi Great House in space, time, and paradigm, in Anasazi Regional Organization and the Chaco System, edited by D. E. Doyel, pp. 101-122. Maxwell Museum of Anthropology Anthropological Papers No. 5. University of New Mexico, Albuquerque.

Gorenflo, Larry J. and Thomas L. Bell

1991 Network analysis and the study of past regional organization, in Ancient Road Networks and Settlement Hierarchies in the New World, edited by C. D. Trombold, pp. 80-98. Cambridge University Press, Cambridge.

Judge, W. James

1984 New light on Chaco Canyon, in New Light on Chaco Canyon, edited by D. G. Noble, pp. 1-12. School of American Research Press, Santa Fe, N.M.

Kane, Allen E.

1993 Settlement analogues for Chimney Rock: A model of 11th & 12th

century northern Anasazi society, in The Chimney Rock Archaeological Symposium, edited by J. M. Malville and G. Matlock, pp. 43-60. U.S.D.A. Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, Co.

Kantner, John

1996 Political competition among the Chaco Anasazi of the American Southwest. Journal of Anthropological Archaeology 15(1):41-105.

Kincaid, Chris (editor)

1983 Chaco Roads Project, Phase I: A Reappraisal of Prehistoric Roads in the San Juan Basin. U.S. Department of the Interior, Bureau of Land Management, Albuquerque, N.M.

Kincaid, Chris, J. R. Stein, and D. F. Levine

1983 Road verification summary, in Chaco Roads Project, Phase I: A Reappraisal of Prehistoric Roads in the San Juan Basin, edited by C. Kincaid, pp. 9-1 - 9-78. U.S. Department of the Interior, Bureau of Land Management, Albuquerque, N.M.

Lekson, Stephen H.

1996 Chaco and Casas. Paper presented at the 61st Annual Meeting Society for American Archaeology, April 12, New Orleans, Louisiana.

Mahoney, Nancy M., A. I. Duff, and K. W. Kintigh

1995 The role of Chacoan outliers in local organization. Paper presented at the 60th Annual Meeting of the Society for American Archaeology, Minneapolis, Minnesota.

Marshall, Michael P.

1992 The Chacoan roads -- A cosmological interpretation, in Proceedings of the Mesa Verde Symposium on Anasazi Architecture and American Design, edited by B. H. Morrow and V. B. Price, pp. 123 - 136. Mesa Verde National Park, Colorado;.

Marshall, Michael P. and Anna Sofaer

1988 Solstice Project archaeological investigations in the Chacoan Project, New Mexico. Ms. in possession of the authors.

Marshall, M. P., J. R. Stein, R. W. Loose, and J. E. Novotny

1979 Anasazi Communities of the San Juan Basin. Public Service Company of New Mexico and New Mexico State Historic Preservation Bureau, Santa Fe.

Mathien, Frances J.

1991 Political, economic, and demographic implications of the Chaco road network, in Ancient Road Networks and Settlement Hierarchies in the New World, edited by C. D. Trombold, pp. 99-110. Cambridge University Press, Cambridge.

Nials, F. L., J. R. Stein, and J. R. Roney

1987 Chacoan Roads in the Southern Periphery: Results of Phase II of the BLM Chaco Roads Project. Cultural Resources Series I. U.S. Department of the Interior, Bureau of Land Management, Albuquerque, N.M.

Powers, Robert P.

1984 Outliers and roads in the Chaco system, in New Light on Chaco Canyon, edited by G. Noble, pp. 45-58. School of American Research Press, Santa Fe, N.M.

Powers, R. P., W. B. Gillespie, and S. H. Lekson

1983 The Outlier Survey: A Regional View of Settlement in the San Juan Basin. U.S. Department of the Interior, National Park Service, Albuquerque, N.M.

Robertson, Benjamin P.

1983 Other New World roads and trails, in Chaco Roads Project, Phase I: A Reappraisal of Prehistoric Roads in the San Juan Basin, edited by C. Kincaid, pp. 2-1 - 2.8. U.S. Department of the Interior, Bureau of Land Management, Albuquerque, N.M.

Roney, John R.

1992 Prehistoric roads and regional integration in the Chacoan system, in Anasazi Regional Organization and the Chaco System, edited by D. E. Doyel, pp. 123-131. Maxwell Museum of Anthropology Anthropological Papers No. 5. University of New Mexico, Albuquerque.

Schelberg, John D.

1982 Analogy, complexity, and regionally-based perspectives, in Recent Research on Chaco Prehistory, edited by W. J. Judge and J. D. Schelberg, pp. 5-22. Reports of the Chaco Center No. 8. Division of Cultural Research, National Park Service, Albuquerque, N.M.

Sebastian, Lynne

1992 The Chaco Anasazi: Sociopolitical Evolution in the Prehistoric Southwest. Cambridge University Press, Cambridge.

Sofaer, A., M. P. Marshall, and R. M. Sinclair

1989 The Great North Road: A cosmographic expression of the Chaco culture of New Mexico, in World Archaeoastronomy, edited by A. F. Aveni, pp. 365-376. Cambridge University Press, Cambridge.

Tainter, Joseph A. and Fred Plog

1994 Structure and patterning: The formation of Puebloan archaeology, in Themes in Southwest Prehistory, edited by G. J. Gumerman, pp. 165-182. School of American Research Press, Santa Fe, N.M.

Tobler, Waldo

1993 Three presentations on geographical analysis and modeling. Technical Report 93-1. National Center for Geographic Information and Analysis, University of California, Santa Barbara.

Toll, H. Wolcott

1991 Material distributions and exchange in Chaco Canyon, in Chaco and Hohokam: Prehistoric Regional Systems in the American Southwest, edited by P. L. Crown and W. J. Judge, pp. 77-108. School of American Research Press, Santa Fe, N.M.

Vivian, R. Gwinn

1996 Chacoan roads: System definition and functional interpretation. Ms. in author's possession.

Wilcox, David R.

1993 The evolution of the Chacoan polity, in Chimney Rock Archaeological Symposium, edited by J. M. Malville and G. Matlock, pp. 76-90. General Technical Report No. RM-227. U.S.D.A. Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, Co.

Windes, Thomas C.

1978 Stone Circles of Chaco Canyon, Northwestern New Mexico. Reports of the Chaco Center No. 5. Division of Cultural Research, National Park Service, Albuquerque, N.M.

1991 The prehistoric road network at Pueblo Alto, Chaco Canyon, New Mexico, in Ancient Road Networks and Settlement Hierarchies in the New World, edited by C. D. Trombold, pp. 111-131. Cambridge University Press, Cambridge.

Winter, Joseph C.

1980 Human adaptations in a marginal environment, in Human Adaptations in a Marginal Environment: The UII Mitigation Project, edited by J. L. Moore and J. C. Winter, pp. 483-520. Office of Contract Archaeology, University of New Mexico, Albuquerque.