Chaco Canyon Timeline

Chaco Canyon Timeline

Ancient DNA Yields Unprecedented Insights into Mysterious Chaco Civilization

The results suggest that a maternal &ldquodynasty&rdquo ruled the society&rsquos greatest mansion for more than 300 years, but concerns over research ethics cast a shadow on the technical achievement

In 1896 archaeologists excavating Pueblo Bonito, a 650-room, multistory brick edifice in northwestern New Mexico&rsquos Chaco Canyon, found the remains of 14 people in a burial crypt. Necklaces, bracelets and other jewelry made up of thousands of turquoise and shell beads accompanied the bones. The artifacts signaled that these individuals were elite members of the ancient Chaco society, one of the most important civilizations in the American Southwest.

The excavations at Pueblo Bonito revealed the splendors of Chaco culture, which flourished between about A.D. 800 and 1250. The ancient Chacoans constructed at least a dozen great houses like Pueblo Bonito in Chaco Canyon during its heyday, and dozens of other Chacoan settlements thrived in what is today the Four Corners region where the borders of New Mexico, Colorado, Arizona and Utah meet. Soon after the excavations ended, archaeologists whisked these human remains off to the American Museum of Natural History (AMNH) in New York City, where most of them have resided ever since.

Every so often researchers take the skulls out of their cardboard storage boxes on the museum&rsquos 5th floor and remove the rest of the bones from wooden drawers lining a nearby hallway, laying them out on long tables to study them. They want to know how these people were related to one another and what this elite group might say about how Chaco society was organized. But they have had only limited clues.

Continuing excavations at Chaco over the years have suggested that most people lived in smaller adobe residences surrounding the great houses, leading the majority of archaeologists to conclude Chaco society was hierarchically structured: Elite groups had dominion over cultural, religious and political life and enjoyed special privileges. Now an analysis of DNA from the Pueblo Bonito remains is providing intimate new details about these elite groups and who belonged to them. In a paper published online this week in Nature Communications researchers report the remains belonged to a single maternal line&mdashwhat the team calls a matrilineal &ldquodynasty&rdquo&mdashthat lasted for centuries. Other scientists hailed the research as a technical tour de force that helps fulfill the promise of ancient DNA to reveal the lives of ancient peoples. But not everyone agrees with the team&rsquos conclusions, and some experts have criticized their decision not to consult with indigenous groups before going ahead with the research.

Archaeologists Douglas Kennett at The Pennsylvania State University, Stephen Plog of the University of Virginia and their colleagues took a multipronged approach to studying the Pueblo Bonito remains. They first obtained direct radiocarbon dates from 11 of the burials, which ranged from between A.D. 800 and 850 for the earliest to about 1130 for the latest. The dates established that the burials spanned a period of some 330 years.

Credit: Roderick Mickens and Adam Watson

Next the team extracted so-called mitochondrial DNA (mtDNA) from the remains. Mitochondria are tiny subcellular bodies that serve as the power plants for living cells, and their DNA is only inherited via the mother. The researchers were able to sequence an average of 98 percent of the mtDNA from nine individuals spanning the entire 330-year chronological sequence. Remarkably, all nine sequences were identical, meaning that each generation descended from the same original maternal ancestor.

Finally, in an effort to tease out specific family relationships, the team sequenced nuclear DNA&mdashwhich is inherited from both the mother and father&mdashfrom six of the burials. These sequences suggested that at least two pairs of individuals were very closely related and probably represented a mother&ndashdaughter and grandmother&ndashgrandson relationship.

The authors argue this elite group, in which power and influence flowed from mothers to their children, ruled at Pueblo Bonito from the earliest days of its founding around A.D. 800. Plog says the group&rsquos clout probably stemmed from its control of ritual practices at Pueblo Bonito, as evidence by the discovery of objects such as carved wooden flutes and ceremonial staffs in the burial crypt.

The study provides &ldquoimpressively high resolution&rdquo of these matrilineal family ties, says Johannes Krause, a paleogeneticist at Max Planck Institute for the Science of Human History in Germany. Jennifer Raff, an anthropologist at the University of Kansas, agrees. &ldquoPaleogenomics approaches like this one can give us insights into the lives of ancient peoples on a scale never before possible.&rdquo Neither were involved with the study.

The team&rsquos interpretation of the genetic results makes sense to a number of outside researchers. &ldquoThis indicates that hereditary leadership was present at the time of Pueblo Bonito&rsquos founding&rdquo rather than gradually developing later as some earlier studies had suggested, says Jill Neitzel, an archaeologist at the University of Delaware. &ldquoThe data show a group of related women, and some men, who can be argued to have been the persistent leaders of Pueblo Bonito for more than 300 years,&rdquo says Paul Reed, an archaeologist with Tucson, Ariz.&ndashbased Archaeology Southwest. &ldquoThis research provides some of the most important information about Chaco in many decades,&rdquo says Paul Minnis, an anthropologist at the University of Oklahoma. &ldquoWhile most every scholar recognizes that Chaco was centrally organized, the nature of that organization has remained maddeningly opaque.&rdquo

Yet Minnis and others question whether the team is right to call this elite group a dynasty, a term that usually refers to kings and queens who exercise sole rule over vast territories and populations. The Pueblo Bonito group &ldquowas clearly an important one,&rdquo says Barbara Mills, an anthropologist at the University of Arizona in Tucson. &ldquoBut was it the only one?&rdquo In her view the findings do not prove their power and influence stretched beyond Pueblo Bonito itself, to include all of Chaco Canyon or even the wider &ldquoChaco world.&rdquo

Nevertheless, the authors argue their results may resolve another longstanding question. Today&rsquos Pueblo peoples claim, on fairly firm archaeological grounds, to be the direct descendants of the Chacoans so do the Navajo, on whose land Chaco Canyon now sits. In many modern Pueblo groups, including the Hopi and Zuni of Arizona and New Mexico, respectively, descent and inheritance are determined by one&rsquos membership in a maternal clan. (A similar arrangement prevails among Orthodox and some Conservative Jews, for whom Jewish identity depends on having a Jewish mother.) Did they inherit this arrangement from their ancient Chacoan ancestors? Or, as archaeologist John Ware of the Amerind Foundation in Arizona has argued, did early kinship ties in Chaco society give way to rule by so-called &ldquosodalities&rdquo based on shared ritual knowledge and practices, such as priests and brotherhoods, in which case some modern Pueblos may have developed their matrilineal organization independently? Kennett, Plog and their colleagues argue their findings support the hypothesis of direct continuity between Chacoan matrilines and those of many Pueblo groups today.

Even as the work lends new support to the affinities between modern indigenous groups and ancient Chacoans, the researchers&rsquo efforts have landed them in a minefield of research ethics. In 1990 Congress passed the Native American Graves Protection and Repatriation Act (NAGPRA), which dictates human remains and other artifacts found on federal or tribal lands must be repatriated to tribal groups if they can successfully establish a direct cultural relationship to them. In some instances such as the famed controversy over the 8,500-year-old Kennewick Man from Washington State, Native Americans and researchers have fought bitterly over who had right of possession.

In the case of the Chaco remains the AMNH decided the NAGPRA did not apply, meaning the researchers were not legally required to get approval from the tribes before conducting research on the remains. In a statement approved by the paper&rsquos 14 authors, the team said that in deciding to not consult the tribes, it relied on the AMNH&rsquos determination that &ldquothe cultural complexity of the region made it impossible to establish a clear ancestor&ndashdescendant relationship with specific modern communities based on existing data.&rdquo The AMNH, in a separate statement, said &ldquothe research had considerable scientific merit with little impact on the artifacts and human remains,&rdquo adding that it had contacted &ldquopotentially affiliated tribes&rdquo during the late 1990s but that &ldquonone came forward to claim affiliation.&rdquo

Credit: Roderick Mickens and Adam Watson

But that decision does not sit well with some critics. &ldquoDespite the fact the authors&rsquo work was technically legal, the ethics here are questionable,&rdquo says Chaco researcher Ruth Van Dyke of Binghamton University in New York State. &ldquoStudies using ancient indigenous DNA should not be done without tribal consultation.&rdquo

Rebecca Tsosie, a law professor of Native American descent at the University of Arizona who specializes in tribal and U.S. Indian law, agrees. &ldquoI am dismayed that there was not an effort to engage contemporary tribal leaders prior to undertaking and publishing this study,&rdquo Tsosie says, adding that the research is a &ldquoprime example&rdquo of &ldquoa study by cultural outsiders to dictate the truth of the history and structure of governance of the cultural insiders, Pueblo Indian nations.&rdquo

Team member George Perry, an ancient DNA expert at Penn State, says that whereas the researchers did not formally consult with tribal leaders nor seek their approval to carry out the study beforehand, he is now &ldquoworking diligently to engage with multiple groups in the Southwest&rdquo to &ldquopresent and discuss the results of the research.&rdquo Getting the blessing of indigenous groups may be key to further research because there are other burials at Pueblo Bonito and other Chacoan sites yet to be studied. Moreover, some archaeologists say, some indigenous people might eventually opt to have their own DNA sequenced to see how closely related they might be to ancient Chacoan ancestors&mdasha step taken by at least one Washington State tribal group that turned out to have a close genetic affiliation with Kennewick Man. In that example the scientific evidence backed up tribal arguments for repatriation of what they call &ldquoThe Ancient One,&rdquo and its remains were reinterred by Northwest tribes on February 18 in a secret location.

Some archaeologists are hoping the new study will be just a first step toward a fuller and more detailed understanding of how the ancient Chacoans lived. &ldquoHow this matriline functioned in the ritual, social and political life of the Chacoans demands more research,&rdquo Minnis says. Until other burials can be studied, &ldquowe cannot answer the question as to whether the Pueblo Bonito matriline was recognized only by that community or by Chaco as a whole.&rdquo

Chaco Resources

The following published texts on Chaco Canyon and Aztec Ruins are no longer in print. They are now digitally available thanks to Andrew W. Mellon funding for the Chaco Research Archive in collaboration with the University of Virginia’s Digital Library Production Services.

Texts from the University of Virginia Digital Library Production Services

If you encounter any difficulties or if you find problems with the texts, please let us know or use the feedback section of the Digital Collections website to inform the library directly. There is also a “Help” section of the Digital Collections website that explains its various tools and functions.

Donald D. Brand, Florence M. Hawley, and Frank C. Hibben, et al.

  • 1937 Tseh So, a small house ruin, Chaco canyon, New Mexico. Albuquerque, N. M. Preliminary Report . University of New Mexico Bulletin No. 308, Anthropological Series 2(2). University of New Mexico, Albuquerque. University of Virginia Library Digital Collections, 2005.

Judd, Neil Merton.

  • 1964 The Architecture of Pueblo Bonito . Smithsonian Miscellaneous Collections 147(1).Smithsonian Institution, Washington, D.C. University of Virginia Library Digital Collections, 2005.
  • 1959 Pueblo del Arroyo, Chaco Canyon, New Mexico . Smithsonian Miscellaneous Collections 138(1).Smithsonian Institution, Washington, D.C.
  • 1954 The material culture of Pueblo Bonito . Smithsonian Miscellaneous Collections 124.Smithsonian Institution, Washington, D.C. University of Virginia Library Digital Collections, 2005

Kluckhohn, Clyde and Paul Reiter (editors)

  • 1939 Preliminary report on the 1937 excavations, Bc 50-51, Canyon, New Mexico, with some distributional analyse s . University of New Mexico Bulletin 345, Anthropological Series 3(2). University of New Mexico, Albuquerque. University of Virginia Library Digital Collections. 2005.

Texts from the American Museum of Natural History Research Library, Scientific Publications

The following texts are publicly available via The American Museum of Natural History, Research Library.

Morris, Earl Halstead.

  • 1928 Notes on excavations in the Aztec ruin . Anthropological papers of the American Museum of Natural History. v. 26, Part IV, pp. 259-420.
  • 1927 The beginnings of pottery making in the San Juan area unfired prototypes and the wares of the earliest ceramic period. Anthropological papers of the American Museum of Natural History. v. 28, pt. II, pp. 125-198.
  • 1924 Burials in the Aztec ruin The Aztec ruin annex . Anthropological papers of the American Museum of Natural History. v. 26, Part III-IV, pp. 139-257.
  • 1921 The house of the great kiva at the Aztec ruin . Anthropological papers of the American Museum of Natural History. v. 26, Part II, pp. 109-138.
  • 1918 The Aztec ruin . Anthropological papers of the American Museum of Natural History. v. 26, Part I, pp. 3-108.

Pepper, George Hubbard

Publications in Archeology, Chaco Canyon Studies, National Park Service

The following texts were digitized by the National Park Service Denver Service Center and are now publicly available via the Chaco Research Archive.

Hayes, Alden C., David M. Brugge, and W. James Judge

  • 1981 Archeological Surveys of Chaco Canyon, New Mexico . Publications in Archeology 18A, Chaco Canyon Studies. National Park Service, Washington, D.C.

Lekson, Stephen H.

Mathien, Frances Joan

Mathien, Frances Joan (editor)

  • 1997 Ceramics, Lithics and Ornaments of the Prehistoric People of Chaco Canyon. Volume 1. Ceramics . Publications in Archeology 18G, Chaco Canyon Studies. National Park Service, Santa Fe.
  • 1997 Ceramics, Lithics and Ornaments of the Prehistoric People of Chaco Canyon. Volume 2. Lithics . Publications in Archeology 18G, Chaco Canyon Studies. National Park Service, Santa Fe.
  • 1997 Ceramics, Lithics and Ornaments of the Prehistoric People of Chaco Canyon. Volume 3. Lithics and Ornaments . Publications in Archeology 18G, Chaco Canyon Studies. National Park Service, Santa Fe.
  • 1985 Environment and Subsistence of Chaco Canyon, New Mexico . Publications in Archeology 18E, Chaco Canyon Studies. National Park Service, Albuquerque.

Mathien, Frances Joan and Thomas C. Windes (editors)

  • 1987 Investigations at the Pueblo Alto Complex, Chaco Canyon, New Mexico, 1975-1979. Volume III, Part 1 . Artifactual and Biological Analyses. Publications in Archeology 18F, Chaco Canyon Studies. National Park Service, Santa Fe.
  • 1987 I nvestigations at the Pueblo Alto Complex, Chaco Canyon, New Mexico, 1975-1979. Volume III, Part 2 . Artifactual and Biological Analyses. Publications in Archeology 18F, Chaco Canyon Studies. National Park Service, Santa Fe.
  • 1987 Investigations at the Pueblo Alto Complex, Chaco Canyon, New Mexico, 1975-1979. Volume IV . Artifactual and Biological Analyses. Publications in Archeology 18F, Chaco Canyon Studies. National Park Service, Santa Fe.

McKenna, Peter J. and Marcia L. Truell

Windes, Thomas C.

  • 1987 Investigations at the Pueblo Alto Complex, Chaco Canyon, New Mexico, 1975-1979. Volume I. Summary of Tests and Excavations at the Pueblo Alto Community . Publications in Archeology 18F, Chaco Canyon Studies. National Park Service, Santa Fe.
  • 1987 Investigations at the Pueblo Alto Complex, Chaco Canyon, New Mexico, 1975-1979. Volume II, Part 1. Architecture and Stratigraphy . Publications in Archeology 18F, Chaco Canyon Studies. National Park Service, Santa Fe.
  • 1987 Investigations at the Pueblo Alto Complex, Chaco Canyon, New Mexico, 1975-1979. Volume II, Part 2. Architecture and Stratigraphy . Publications in Archeology 18F, Chaco Canyon Studies. National Park Service, Santa Fe.

White Papers, Chaco Culture National Historical Park, Intermountain Regional Office, National Park Service

Van Dyke, Ruth, Stephen Lekson, and Carrie Heitman with a contribution by Julian Thomas

  • 2016 Chaco Landscapes: Data, Theory and Management. White Paper produced for the National Park Service in partial fulfillment of CESU Master Agreement P14AC00979, Project Number: UCOB-109 to Chaco Culture National Historical Park, New Mexico by the University of Colorado, Boulder. Retrieved from the Chaco Research Archive, .

Reports of the Chaco Center, Branch of Cultural Research, National Park Service

The following texts were digitized by the National Park Service Denver Service Center and are now publicly available via the Chaco Research Archive.

Chaco Culture National Historical Park

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Chaco Culture National Historical Park, area of Native American ruins in northwestern New Mexico, U.S. It is situated some 45 miles (70 km) south of Bloomfield and about 55 miles (90 km) northeast of Gallup. The park was established in 1907 as Chaco Canyon National Monument and was redesignated and renamed in 1980 it became a UNESCO World Heritage site in 1987. The park occupies an area of 53 square miles (137 square km), which consists of a canyon dissected by the Chaco and Gallo washes. The name probably derives from the Spanish word chaca, which may be a translation of a Navajo word for canyon. The site was an administrative, economic, and ceremonial centre of the Ancestral Pueblo (Anasazi) people from ad 850 to 1250. The Ancestral Pueblos were ancestors of the modern Pueblo Indians.

The buildings are known for their sophisticated architecture and are connected by a series of straight, wide roadways that radiate outward like spokes on a wheel. They were also once connected to dozens of other settlements in the region by some 400 miles (650 km) of engineered roads. Turquoise jewelry, obsidian blades, and macaw feathers from Mesoamerica suggest that Chaco lay along an important trade route extending far southward. The park contains 13 major ruins and more than 400 smaller archaeological sites. Pueblo Bonito (built mainly in the 10th century), the largest and most completely excavated site, contained about 800 rooms and 39 kivas (round, subterranean ceremonial chambers). The excavations indicate that the inhabitants excelled in pottery, jewelry, architecture, and masonry. Artifacts are displayed at the visitor centre.

A 9-mile (15-km) paved road allows access to five major sites with self-guiding hiking trails backcountry hiking trails are also available. The park’s desert climate supports coyotes, bobcats, jackrabbits, prairie dogs, kangaroo rats, antelope ground squirrels, and lizards. The park is culturally linked with nearby Aztec Ruins National Monument (north) and Mesa Verde National Park in Colorado (northwest). The large Navajo Indian Reservation of Arizona, New Mexico, and Utah is just west of the site, and other nearby national monuments include Canyon de Chelly, El Malpais, and El Morro.

This article was most recently revised and updated by Amy Tikkanen, Corrections Manager.

Chaco Canyon - The Solstice Project

Since its release in 2000, our award-winning film, &ldquoThe Mystery of Chaco Canyon,&rdquo has aired more than 10,000 times on 95% of PBS stations across the country. New Mexico PBS has broadcast this full-length documentary more than 90 times. Learn more about our captivating exploration of ancient astronomy in the American Southwest, directed by the Solstice Project founder Anna Sofaer and narrated by Robert Redford.

Unveiling the ancient astronomy of southwestern Pueblo Indians

56 minutes, Color
Grade Level: 7-12, College, Adult
US Release Date: 1999 Copyright Date: 1999
ISBN: 1-56029-812-X

Directed by Anna Sofaer
Produced by The Solstice Project
Narrated by Robert Redford
Written by Anna Sofaer and Matt Dibble
Music by Michael Stearns
(check your local station for listings)

Rent and stream the full version HERE.

"I am grateful to Anna Sofaer for involving me in her decades-long passion to explain this extraordinary and magical place."
Robert Redford

"The video. becomes part of the ongoing dialogue between archeologists, anthropologists, and native peoples. (It's) a multi-level phenomenon, like Chaco, which embraces complexity, beauty and mystery."
Rina Swentzell, Architect, Santa Clara Pueblo

"A captivating look at one of the most impressive archaeological sites in North America. Anna Sofaer reveals the solar and lunar complexity of Chacoan buildings with impressive visual economy and clarity. In the process, we get a whole new picture of the intelligence at work behind Chacoan society and its architecture. The Mystery of Chaco Canyon interweaves a narrative that is both attentive to indigenous thought and values, and robustly grounded in the rigors of scientific method. Well-paced and absorbing, simultaneously poetic and analytical, this film provides a new benchmark of understanding for serious studies of ancestral-Pueblo astronomy and culture."
Dr. Peter Whiteley, Dept. of Anthropology, American Museum of Natural History

THE MYSTERY OF CHACO CANYON examines the deep enigmas presented by the massive prehistoric remains found in Chaco Canyon in northwestern New Mexico. It is the summation of 20 years of research. The film reveals that between 850 and 1150 AD, the Chacoan people designed and constructed massive ceremonial buildings in a complex celestial pattern throughout a vast desert region. Aerial and time lapse footage, computer modeling, and interviews with scholars show how the Chacoan culture designed, oriented and located its major buildings in relationship to the sun and moon. Pueblo Indians, descendants of the Chacoan people, regard Chaco as a place where their ancestors lived in a sacred past. Pueblo leaders speak of the significance of Chaco to the Pueblo world today.

The film challenges the notion that Chaco Canyon was primarily a trade and redistribution center. Rather it argues that it was a center of astronomy and cosmology and that a primary purpose for the construction of the elaborate Chacoan buildings and certain roads was to express astronomical interests and to be integral parts of a celestial patterning.

While the Chacoans left no written text to help us to understand their culture, their thoughts are preserved in the language of their architecture, roads and light markings. Landscape, directions, sun and moon, and movement of shadow and light were the materials used by the Chacoan architects and builders to express their knowledge of an order in the universe.

This is the long-awaited sequel to Anna Sofaer's classic film THE SUN DAGGER, which changed forever our perception of America's earliest Indian peoples.

Awards for The Mystery of Chaco Canyon

  • Taos Talking Picture Festival
  • Silver Plaque, The Chicago International Television Competition
  • Bronze Plaque, Columbus International Film & Video Festival
  • Honorable Mention, The Archaeology Channel International Film & Video Festival
  • American Museum of Natural History, New York
  • National Museum of National History, Smithsonian Institution, Washington DC
  • Aboriginal Voices Festival, Toronto
  • Hot Spring Documentary Film Festival
  • Heard Museum Indigenous Film Festival

Audience Ratings for the Summer 2000 PBS Premiere of The Mystery of Chaco Canyon

The average PBS primetime audience rating is 1.6. The PBS premiere of The Mystery of Chaco Canyon was in Summer 2000 and garnered significantly higher ratings in most markets and exceptional ratings in the markets listed below. Since that time, our film receives consistent rebroadcasting on PBS stations.

  • San Diego - 4.6
  • Denver & St. Louis - 4.0
  • Phoenix - 3.9
  • Oklahoma City - 3.6
  • Dallas - 3.5
  • Salt Lake City - 3.4
  • Sacramento - 3.3

The Mystery of Chaco Canyon" and "The Sun Dagger" are available for HOME use and for EDUCATIONAL use. The EDUCATIONAL version has an accompanying Teachers Study Guide. Half hour versions of both films are avaliable for teaching (please email for this option).

Spoiling Park Resources

While the footprint of Chaco Culture National Historical Park itself is small, the larger connected cultural landscape is vast. For many Native peoples, the boundaries of the park do not encompass all that is important spiritually and culturally.

The park’s location within the San Juan Basin, a geologic formation rich in fossil fuel resources, creates an ongoing threat to the park’s cultural resources. The oil and gas industry has already heavily developed the region’s checkerboard of private, state, federal and tribal lands. Such development has scarred the landscape with tens of thousands of oil and gas wells and roads that now cut through the Chaco landscape, trafficked by trucks and heavy equipment, which destroy and endanger numerous ancient archeological sites. This only makes it more important that federal lands in the region be protected for their cultural values, not opened to even more drilling.

The Bureau of Land Management’s Farmington Field Office in New Mexico has already leased more than 91 percent of Chaco’s surrounding public land to the oil and gas industry. Gas flares light up the dark night skies, and pollution from flares and leaking infrastructure endanger the health of the Native American communities who have lived in the area for centuries. Rampant methane waste, particularly in the San Juan Basin, has created a 2,500-square-mile methane cloud — the size of the state of Delaware — over the Four Corners region and national parks including Chaco.

Development around Chaco Culture National Historical Park (click map to enlarge) + Click to download PDF

All of the drilling pushed forward by this administration has taken place without meaningful consultation with the local tribal communities. In March 2020 the administration proposed a Resource Management Plan Amendment for the Farmington Field Office that would open most areas for oil and gas drilling that are currently off-limits, including directly up to the park’s boundaries.

Fighting back, a historic coalition of the Pueblo and Navajo peoples in the region have come together to protect the landscape. Along with the entire New Mexico congressional delegation, they are advancing legislation to permanently protect the area surrounding the park from new oil and gas development.

The ancient community of Chaco Canyon

New Mexico is known as the “land of enchantment.” Among its many wonders, Chaco Canyon stands out as one of the most spectacular. Part of Chaco Culture National Historical Park, Chaco Canyon is among the most impressive archaeological sites in the world, receiving tens of thousands of visitors each year. Chaco is more than just a tourist site however, it is also sacred land. Pueblo peoples like the Hopi, Navajo, and Zuni consider it a home of their ancestors.

The canyon is vast and contains an impressive number of structures—both big and small—testifying to the incredible creativity of that people who lived in the Four Corners region of the U.S. between the 9th and 12th centuries. Chaco was the urban center of a broader world, and the ancestral Puebloans who lived here engineered striking buildings, waterways, and more.

Petroglyphs, Chaco Canyon (photo: KrisNM, CC BY-NC-ND 2.0)

Chaco is located in a high, desert region of New Mexico, where water is scarce. The remains of dams, canals, and basins suggest that Chacoans spent a considerable amount of their energy and resources on the control of water in order to grow crops, such as corn. Today, visitors have to imagine the greenery that would have filled the canyon.

Astronomical observations clearly played an important role in Chaco life, and they likely had spiritual significance. Petroglyphs found in Chaco Canyon and the surrounding area reveal an interest in lunar and solar cycles, and many buildings are oriented to align with winter and summer solstices.

The great kiva at Chetro Ketl, Chaco Canyon, New Mexico (National Park Service)

Great Houses

“Downtown Chaco” features a number of “Great Houses” built of stone and wood. Most of these large complexes have Spanish names, given to them during expeditions, such as one sponsored by the U.S. army in 1849, led by Lt. James Simpson. Carabajal, Simpson’s guide, was Mexican, which helps to explain some of the Spanish names. Great Houses also have Navajo names, and are described in Navajo legends. Tsebida’t’ini’ani (Navajo for “covered hole”), nastl’a kin (Navajo for “house in the corner”), and Chetro Ketl (a name of unknown origin) all refer to one great house, while Pueblo Bonito (Spanish for “pretty village”) and tse biyaa anii-ahi (Navajo for “leaning rock gap”) refer to another.

Pueblo Bonito, Chaco Canyon, New Mexico (photo: Paul Williams, CC BY-NC 2.0)

Multistoried rooms, Pueblo Bonito, Chaco Canyon, New Mexico (photo: Jacqueline Poggi, CC BY-NC-ND 2.0)

Pueblo Bonito is among the most impressive of the Great Houses. It is a massive D-shaped structure that had somewhere between 600 and 800 rooms. It was multistoried, with some sections reaching as high as four stories. Some upper floors contained balconies.

There are many questions that we are still trying to answer about this remarkable site and the people who lived here. A Great House like Pueblo Bonito includes numerous round rooms, called kivas. This large architectural structure included three great kivas and thirty-two smaller kivas. Great kivas are far larger in scale than the others, and were possibly used to gather hundreds of people together. The smaller kivas likely functioned as ceremonial spaces, although they were likely multi-purpose rooms.

Doorway, Pueblo Bonito, Chaco Canyon (photo: Thomson20192, CC BY 2.0)

Among the many remarkable features of this building are its doorways, sometimes aligned to give the impression that you can see all the way through the building. Some doorways have a T shape, and T-shaped doors are also found at other sites across the region. Research is ongoing to determine whether the T-shaped doors suggest the influence of Chaco or if the T-shaped door was a common aesthetic feature in this area, which the Chacoans then adopted.

Recently, testing of the trees (dendroprovenance) that were used to construct these massive buildings has demonstrated that the wood came from two distinct areas more than 50 miles away: one in the San Mateo Mountains, the other the Chuska Mountains. About 240,000 trees would have been used for one of the larger Great Houses.

Chacoan Cultural Interactions

Traditionally, we tend to separate Mesoamerica and the American Southwest, as if the peoples who lived in these areas did not interact. We now know this is misleading, and was not the case.

Chacoan culture expanded far beyond the confines of Chaco Canyon. Staircases leading out of the canyon allowed people to climb the mesas and access a vast network of roads that connected places across great distances, such as Great Houses in the wider region. Aztec Ruins National Monument (not to be confused with ruins that belonged to the Aztecs of Mesoamerica) in New Mexico is another ancestral Puebloan site with many of the same architectural features we see at Chaco, including a Great House and T-shaped doorways.

Aztec Ruins National Monument, New Mexico (photo: Jasperdo, CC BY-NC-ND 2.0)

Cylindrical Jar from the Pueblo Bonito, Chaco Canyon, New Mexico, 3 5/8 inches in diameter (National Anthropological Archives, Smithsonian Institution)

Archaeological excavations have uncovered remarkable objects that animated Chacoan life and reveal Chaco’s interactions with peoples outside the Southwestern United States. More than 15,000 artifacts have been unearthed during different excavations at Pueblo Bonito alone, making it one of the best understood spaces at Chaco. Many of these objects speak to the larger Chacoan world, as well as Chaco’s interactions with cultures farther away. In one storage room within Pueblo Bonito, pottery sherds had traces of cacao imported from Mesoamerica. These black-and-white cylindrical vessels were likely used for drinking cacao, similar to the brightly painted Maya vessels used for a similar purpose.

The remains of scarlet macaws, birds native to an area in Mexico more than 1,000 miles away, also reveal the trade networks that existed across the Mesoamerican and Southwestern world. We know from other archaeological sites in the southwest that there were attempts to breed these colorful birds, no doubt in order to use their colorful feathers as status symbols or for ceremonial purposes. A room with a thick layer of guano (bird excrement) suggests that an aviary also existed within Pueblo Bonito. Copper bells found at Chaco also come from much further south in Mexico, once again testifying to the flourishing trade networks at this time. Chaco likely acquired these materials and objects in exchange for turquoise from their own area, examples of which can be found as far south as the Yucatan Peninsula.

Current Threats to Chaco

The world of Chaco is threatened by oil drilling and fracking. After President Theodore Roosevelt passed the Antiquities Act of 1906, Chaco was one of the first sites to be made a national monument. Chaco Canyon is also a UNESCO World Heritage Site. The Chacoan region extended far beyond this center, but unfortunately the Greater Chacoan Region does not fall under the protection of the National Park Service or UNESCO. Much of the Greater Chaco Region needs to be surveyed, because there are certainly many undiscovered structures, roads, and other findings that would help us learn more about this important culture. Beyond its importance as an extraordinary site of global cultural heritage, Chaco has sacred and ancestral significance for many Native Americans. Destruction of the Greater Chaco Region erases an important connection to the ancestral past of Native peoples, and to the present and future that belongs to all of us.

Go deeper

Stephen H. Lekson, ed. The Architecture of Chaco Canyon, New Mexico ( Salt Lake City: University of Utah Press, 2007).

A new look at some unusual remains found at New Mexico’s Chaco Canyon may change our understanding of when, and how, the culture of the Ancestral Puebloans felt the first stirrings of economic and social complexity.

According to new research, the remains of more than a dozen scarlet macaws — tropical birds whose remains were unearthed at Chaco — turn out to be centuries older than was originally thought, suggesting that the long-distance trade that brought them there likely arose hundreds of years earlier than many archaeologists believed.

What’s more, researchers say, Chaco’s trade in colorful birds and other exotic goods from Mesoamerica, such as turquoise and chocolate, required not just an extensive network but also a degree of social hierarchy, because such prized items were likely controlled by a ceremonial elite.

As a result, the archaeologists note, the new findings suggest that Chaco Canyon’s growing economic reach may actually have been the driving force behind — rather than a mere symptom of — its burgeoning cultural and religious sophistication.

“Our findings suggest that rather than the acquisition of macaws being a side effect of the rise of Chacoan society, there was a causal relationship,” said Dr. Adam Watson of the American Museum of Natural History (AMNH), and lead author of the new study, in a press statement. This skull of a scarlet macaw (Ara macao) was excavated from Pueblo Bonito in New Mexico by researchers from the American Museum of Natural History in 1897. (© AMNH/D. Finnin)

“The ability to access these trade networks, and the ritual power associated with macaws and their feathers, may have been important to forming these hierarchies in the first place.”

The bones of 30 scarlet macaws were originally excavated in 1897 from three rooms in Pueblo Bonito, the largest of the grand, multistory great houses that comprise the ancient complex of Chaco Canyon.

Fourteen of the animals were found in a single chamber, known as Room 38, which seemed to serve as a sort of indoor holding pen for the birds.

Another 16 were found throughout the canyon, often buried among other artifacts such as pottery.

The macaws’ skeletons were kept in storage at AMNH, until Watson and his colleagues decided to conduct radiocarbon tests on them, as part of an ongoing study into the rise of Chaco’s social and cultural development.

Based on other, less-direct evidence, such as the styles of pottery and tree-ring dates from door and roof beams, it’s been widely believed that the macaws and other exotic trade goods dated to the same time that Chaco underwent its greatest and most rapid development, between about 1040 and 1140 CE — a phase sometimes known as Chaco’s florescence, or “the golden century.” Pueblo Bonito was constructed in phases from 850 to about 1150.

“In general, most researchers have argued that emergence of hierarchy, and of extensive trade networks that extended into Mexico, would coincide with what we see as other aspects of the Chaco florescence: roads being built outward from Chaco and the formation of what are called Chaco outliers that mimic the architecture seen in the cultural center,” said University of Virginia archaeologist Dr. Stephen Plog, who co-authored the study.

“For many years, that was the dominant model.” [Read about an outlier great house recently discovered Arizona: “‘Impressive’ Pueblo Great House, Dozens of Ruins Found in Petrified Forest National Park”]

However, radiocarbon analysis of 14 macaw bones taken from three chambers in Pueblo Bonito showed that the birds dated back as far as 1,130 years — more than 150 years before Chaco’s trade with Mesoamerica was thought to have begun.

“By directly dating the macaws, we have demonstrated the existence of long-distance networks throughout much of this settlement’s history,” Watson said. [Learn about Mesoamerica’s even stronger influence in Arizona: “Mesoamerican ‘Fool’s Gold’ Mirrors Found in Arizona Reveal Ties to Ancient Mexico“]

Twelve of the 14 animals studied turned out to predate Chaco’s “golden century,” the experts noted, with 7 of them dating to the 800s.

Therefore, the researchers surmise that earlier access to these scarlet macaws must suggest an earlier development of a religious elite at Chaco Canyon, because the birds impart strong ceremonial significance in Puebloan society.

“Birds are a part of nature, but they are also agents with magical properties that can be put to human use,” said team member Dr. Peter Whiteley, curator of anthropology at AMNH.

Scarlet macaws and their red feathers are strongly associated with the south, one of the four cardinal points that comprise the Puebloan cosmology, the experts noted, and macaw feathers have frequently been found on ritual artifacts such as staffs and garments.

“Flight, or just the appearance of certain birds or the use of their feathers, is believed to motivate the fall of rain or snow, as well as the seasons, the sunshine, and the heat,” Whiteley said. The feathers of scarlet macaws have been used in Pueblo ceremonial items such as prayer sticks and masks, and acquiring and caring for the birds were likely the work of ritual elites, archaeologists say.

With so much importance resting on the exotic birds, their acquisition and care was likely the job of a ritual class that was tasked with overseeing ceremonial duties at Chaco Canyon.

And indeed, previous research by the team has already suggested that Chaco became socially and religiously complex before it became so architecturally monumental.

In 2010, Watson and his colleagues studied a pair of human remains found interred in Pueblo Bonito’s Room 33, widely presumed to be members of an elite class, since they were buried amid a wealth of grave goods such as seashells, turquoise beads, and flutes. Radiocarbon analysis showed that the pair dated to between 750 and 850 CE — again, centuries before Chaco’s heyday.

Taken together, the team says, these clues suggest that Chaco society developed a complex, hierarchical structure not only earlier than expected, but also more gradually.

If so, the majestic monuments that we associate with Chaco Canyon today were constructed hundreds of years after its people had already built economic ties with Mesoamerica, and a ritual class within its own boundaries. [See how an aerial drone discovered a Chacoan village: “‘Hidden Architecture’ of 1,000-Year-Old Village Discovered in New Mexico“]

“We propose that the hierarchical sociopolitical foundation of Chacoan society was established during the initial era of construction of the great houses, and that this foundation was reinforced during the late ninth and 10th centuries by the acquisition of scarlet macaws and other cosmologically powerful agents from Mesoamerica,” Plog said.

“Sociopolitical hierarchies evolved over the course of nearly two centuries before taking the more visible forms seen in the Chaco florescence.

“As in many parts of the world, this was a long-term process rather than a brief, abrupt transformation.”

Major Anasazi Regions and Sites

At least from the time of Jesus, and for possibly 1,500 years before, the Anasazi occupied a huge chunk of mostly arid and barren real estate in the Four Corners Area of the American Southwest where four modern states – Colorado, New Mexico, Arizona and Utah – join at one point. Many 19th century archaeologists believed that the Anasazi disappeared after they abandoned major cities like Mesa Verde and Chaco near the end of the 13th century. Now, we know that they didn’t just vanish into thin air, but migrated to the Río Grande Valley, Hopi, Zuni, Acoma and other pueblos in Arizona and New Mexico. (See the SW Cultures Map). In fact, modern scientists have extended the historical timeline of the Anasazi to at least 1700 and, often, right up to the present to encompass the modern Puebloan descendants of the Anasazi.

Scattered throughout the immense area once occupied by the Anasazi are hundreds of thousands of sites, ranging from caves and individual campsites in the open to multi-story adobe pueblos and magnificent cliff-side stone cities. Most of the major sites are within the boundaries of national or state parks and monuments. On the following pages we deal mostly with such major sites since they are generally more accessible and better maintained.

The area of primary Anasazi occupation, as shown on the SW Cultures Map, overlaps with areas occupied by other ancient Southwest cultures, including the Mogollon, Hohokam and Hakataya. In the following pages we focus on the purer, non-overlapping part of the Anasazi territory, bounded on the south by a line running roughly from Flagstaff, Arizona, to a point about 50 miles south of Albuquerque, New Mexico. Modern archaeologists break this area of Anasazi cultural influence into six distinct districts or regions: Chaco, Northern San Juan, Kayenta, Virgin Kayenta, Cíbola and Río Grande. (See the Ancient Sites map).
Chaco Region
The Chaco Region is located in the northwest corner of New Mexico and centered on Chaco Canyon, the area of probably the highest level of societal and cultural development of all the Anasazi regions. (See the Chaco Region Map).

Included in the Chaco Region are the following major Anasazi sites:

  • Aztec Ruins National Monument, near Farmington, Aztec and Bloomfield, New Mexico
  • Chaco Culture National Historic Park (including Pueblo Bonito and Chetro Ketl), south of Farmington, New Mexico
  • El Malpais National Monument, south of Grants, New Mexico

Northern San Juan (Mesa Verde) Region
The Northern San Juan Region, sometimes called the Mesa Verde Region, occupies the southwestern corner of Colorado and the southeastern corner of Utah. (See the Northern San Juan Region Map). Included in this region are America’s best-known Anasazi ruins at Mesa Verde.

Included in or near the Northern San Juan Region are Anasazi sites at:

  • Arches National Park, near Moab, Utah
  • Canyonlands National Park, near Moab, Utah
  • Cedar Mesa Area, near Blanding, Utah
  • Chimney Rock Archaeological Area, near Chimney Rock, Colorado
  • Dominguez and Escalante Pueblos, at the BLM Anasazi Heritage Center near Dolores, Colorado
  • Edge of the Cedars State Park, near Blanding, Utah
  • Grand Gulch Primitive Area, near Blanding, Utah
  • Hovenweep National Monument, near Blanding, Utah
  • Lowry Pueblo Ruins, near Pleasant View, Colorado
  • Mesa Verde National Park, near Cortez, Colorado
  • Natural Bridges National Monument, near Blanding, Utah
  • Newspaper Rock State Monument, near Monticello, Utah
  • Three Kiva Pueblo, near Moab, Utah
  • Ute Mountain Tribal Park, near Cortez, Colorado
  • Yellow Jacket Pueblo Ruins, near Pleasantville, Colorado
  • Yucca House National Monument, near Cortez, Colorado

Kayenta Region
Largest of the Anasazi regions, Kayenta spreads across northern Arizona into southern Utah and northwestern Colorado. Some researchers identify the western part of the Kayenta Region as the Virgin Kayenta. The Virgin subregion stretches from the midpoint on the Utah-Arizona border west to a point about 40 or 50 miles into Nevada. Bounded by the Grand Canyon on the south, the area is named for the Virgin River, which originates in southwestern Utah and joins the Colorado River in Nevada. (See the Virgin Kayenta Region Map and the Kayenta Region Map).

Included in or near the Kayenta Region are Anasazi sites at:

  • Canyon De Chelly National Monument, near Grants, New Mexico
  • Capitol Reef National Park, near Torrey, Utah
  • Glen Canyon National Recreation Area, near Ticaboo, Utah
  • Holol’ovi Ruins State Park, near Winslow, Arizona
  • Navajo National Monument (including Betatakin, Keet Seel and Inscription House), near Kayenta, Arizona
  • Petrified Forest National Park, near Holbrook, Arizona

Cíbola Region
Straddling the Arizona-Utah state border at a point in line with Winslow, Arizona, on the west and Albuquerque, New Mexico, on the east, Cíbola is by far the smallest of the Anasazi regions. Centered on the existing Zuni Indian Reservation, it includes El Morro National Monument, which contains the remains of Anasazi culture. (See the Cíbola Region Map).

Included in the Cíbola Region are:

  • El Morro National Monument and Inscription Rock, east of Zuni, New Mexico
  • Ruins in and around the Zuni Pueblo and Indian Reservation, including Hawikuh, Halona (now Zuni) and Heshotauthla

Río Grande Region
Seventy to eighty miles wide and straddling the river for which it is named, the Río Grande Region lies entirely in New Mexico. It reaches from a point about 25 miles south of the Colorado border to a point about 50 miles south of Albuquerque. (See the Río Grande Region Map) With the exception of Hopi, Zuni, Acoma and Laguna, it encompasses the majority of the present day homes of Anasazi descendants, including the 14 Río Grande pueblos.

Though ancient Southwestern peoples occupied the region for millennia, most of the major Anasazi sites in this region are newer than those in other regions. Among the major sites are:

Chacoan Roads

Jackson stairway

One of the most remarkable aspects of Chaco Culture, at least from a modern perspective, is the extensive system of finely engineered roads both within the canyon and extending out a considerable distance to the outlying sites throughout the San Juan Basin and beyond. These roads are remarkably side, straight, and carefully constructed. The ones inside the canyon average about 15 feet in width, while the ones going out toward the outliers tend to be about twice that wide.

Perhaps the most significant aspect of the Chacoan roads is their straightness. The roads are generally aligned very precisely, and continue for considerable distances with the same alignment without curving or adapting to the landscape as modern roads and trails usually do. When they do change direction, it tends to be with sharp, angled turns rather than gentle curves. When a road comes to a mesa or cliff face, rather than curving or turning it will often go straight up with stairs carved into the rock and continue on top with its original alignment. The most spectacular example of this in Chaco Canyon is the Jackson Stairway above Chetro Ketl, which can be seen (though not climbed!) on the Pueblo Alto Trail. Other stairways can be seen behind Hungo Pavi and east of Casa Rinconada. On more gentle slopes there are sometimes stairways with steps constructed of masonry rather than carved into the rock. One of these masonry stairways can be seen on the Pueblo Alto Trail. Occasionally, the people constructed massive earthen and masonry ramps to conduct people to the tops of cliffs. One example (near Chetro Ketl) can be viewed from the Pueblo Alto Trail.

The roads are generally not visible on the ground and have been identified mainly through aerial photography. There are some places along the Pueblo Alto Trail where identified road segments have been indicated with signs.

Although many road segments have been identified from aerial photographs and confirmed on the ground, only a few of these segments have been found to connect to each other to form roads that run continuously for significant distances. The best documented examples of long roads are the Great North Road, which starts just east of Pueblo Alto and runs north to Kutz Canyon, where it stops rather abruptly at the canyon edge, and the South Road, which leaves the canyon at South Gap and runs toward (though not quite to) the outlying communities in the Red Mesa Valley to the south. The other road alignments consist of discontinuous segments. Some archaeologists believe that these originally were connected by other road segments, which have since eroded away, to form continuous roads from Chaco Canyon to outlying communities in various parts of the San Juan Basin. Others argue that the road segments did not connect to form roads, and were more symbolic than practical.

Many of the road segments associated with outlying great houses do not seem to run continuously to Chaco Canyon or anywhere else. Instead they start at the great house and run a short distance from it, often in the direction of notable landscape features or other great houses. This suggests that at least at these outliers many road segments were intended to be symbolic connections to places of importance rather than everyday means of transportation. In fact, some archaeologists argue that all of the roads were more symbolic than practical, and that they may have been primarily religious in function. One of the pieces of evidence offered for this view is the fact that some of the modern pueblos, particularly Zuni and Acoma, have sacred trails that they use in ritual pilgrimages to important ceremonial locations such as Zuni Salt Lake. Though these trails are nowhere near as formal or elaborate as the Chacoan roads, there are some striking similarities, and in fact some of the modern trails use surviving prehistoric road segments in some places. Since these pueblos have very strong traditions tying them to Chaco Canyon, their use of trails is a key consideration in evaluating the functions of Chacoan roads. Another piece of evidence for a ceremonial function is the size of the roads. In a society that had neither pack animals nor wheeled vehicles it is unclear what, if any, practical need could have required roads thirty feet wide. The enormous amount of labor invested in the construction of the roads at a scale well beyond practical need suggests a higher purpose than mere transportation.

Despite the strong arguments for a primarily ritual function, many archaeologists do still argue that there were at least some practical functions for the roads. Experiments have shown that walking on one of the surviving road segments requires considerably less energy than walking the same distance on the unmodified terrain next to the road, suggesting that even if the primary purpose of the roads was religious they would certainly have been useful for transportation as well. Another possible function for the roads, in addition to personal transportation, is transportation of goods. An astonishing volume and variety of material was imported to Chaco Canyon, including approximately 200,000 wooden beams used in the construction of the great houses. These beams, often whole trunks of ponderosa pine, had to be brought in from considerable distances, mostly from the Chuska Mountains and Mount Taylor. Since walking on the roads is easier than walking off of them, they would have been quite useful in carrying such heavy loads such great distances, even if this was not their primary purpose.

Whether the Chacoan roads were ritual or practical in purpose and use, they are certainly impressive, and they stand as clear evidence of the enormous amount of thought and effort that went into the Chaco system.

Chacoan roads running north from Pueblo Alto.

Watch the video: The Cannibals Of The Four Corners Native American Documentary. Timeline