Unlocking Chaco's mysteries


Archaeologists reveal novel insights on life in Chaco Canyon, USA.


Chaco Canyon, New Mexico, with its famed ‘Great Houses’, is one of the iconic locations of Native American history. It lies in the heart of the San Juan Basin, whose semi-arid landscape and irregular rainfall created a major challenge for ancestral Pueblo. Intense debate has surrounded Chaco for generations. One enduring school of thought argues that the canyon and its magnificent pueblos were a ceremonial location where hundreds of people congregated for elaborate ceremonies, especially at the solstices, important landmarks in the agricultural year. There is no question that Chaco was indeed an important ritual location, but did significant numbers of people live there?


We now know that as many as 2200 people did—permanently. A new generation of research has shown that the Chacoans interacted with their demanding ecosystem in ways that allowed them to adapt and thrive for over a thousand years.


Over the past decade, a team of researchers led by Vernon Scarborough from the University of Cincinnati and other scientists have focused on the issue of sustainability and ancient land practices. Using pollen grains and botanical analysis, also LiDAR mapping, they have documented major changes in the local juniper/piñon woodland with the introduction of agriculture after 500 BC. The new economy caused widespread deforestation during the height of the Chaco culture with its Great Houses between AD 800 and 1140.


The people kept things going by cultivating different crops, while using the local juniper/piñon trees for architecture (pueblo beams), pot firing, food, and firewood. Nevertheless, they conserved piñon pine trees for their nuts. As early as 600 BC, the juniper woodlands were degrading, despite highly skilled use of local water resources. Erosion of junipers led to soil erosion that affected the resilience of the landscape and affected the Chacoans’ ability to resist drought. In the end, the inhabitants gradually moved elsewhere.




Image: Doorway, Pueblo Bonito, Chaco Canyon.

Credit: B Schaller, CC.