Chacoan Voices of Pueblo Bonito

The story of Chaco Canyon unfolds in layered stone and the quiet ledger of tree rings. Pueblo Bonito, the monumental great house at the heart of Chaco (New Mexico), grew between roughly 885 and 1154 CE into an architectural and ceremonial focus with multistory masonry, room suites, and large kivas. Archaeological data indicates that this florescence was the product of long-term regional aggregation: communities across the San Juan Basin participated in the construction of roads, great-house architecture, and ritual exchange networks.

Dendrochronology (tree-ring dating), stratigraphic excavation, and artifact typologies anchor Pueblo Bonito’s main construction phases to the late 9th through the 12th centuries CE. Radiocarbon and tree-ring dates place major building episodes and occupancy across this window, revealing periods of intensive construction around the 10th–11th centuries CE.

Limited evidence suggests Chaco functioned as a regional node for ceremonial activity, craft production, and long-distance exchange (turquoise, shell, timber). While the architectural spectacle implies centralized organization, archaeological patterns also point to complex, multi-scalar social relationships among households, ritual specialists, and visiting groups. The visible monuments at Pueblo Bonito thus reflect both local adaptation to the high desert and far-reaching social ties across the ancient Southwest.

Archaeogenetic sampling from Pueblo Bonito provides a rare window into the biological heritage of Chacoan inhabitants, but the dataset is small (five individuals) and must be treated as preliminary. All five mitochondrial genomes belong to haplogroup B2, a maternal lineage commonly found among Indigenous peoples throughout North, Central, and South America. This consistent presence of B2 across the sampled individuals suggests maternal continuity with Native American maternal lineages that are widespread in the Southwest and beyond.

On the paternal side, two of the male samples carry Y-chromosome haplogroup Q, a lineage that is likewise characteristic of Indigenous populations across the Americas and is often interpreted as reflecting deep precontact paternal ancestry. The co-occurrence of B2 (mtDNA) and Q (Y-DNA) aligns with expectations for local Indigenous ancestry in the prehistoric Southwest, but the small sample count (n = 5) constrains demographic inference.

Archaeogenetic signals here can indicate regional continuity, potential kin networks within great houses, or localized demographic patterns, but distinguishing among these scenarios requires far larger, geographically diverse samples and integration with osteological and archaeological context. In short: the genetic data are consistent with Native American ancestry patterns but are not yet robust enough to resolve migration, kinship structure, or fine-scale population dynamics at Chaco.