US Geological Survey


Date of this Version



Benson, Larry V, 2004, Sources of ancient maize found in Chacoan great houses: United States Geological Survey.


U.S. government work.


Between the 9th and 12th centuries A.D., Chaco Canyon, located near the middle of the high-desert San Juan Basin of north-central New Mexico (fig. 1), was the focus of an unprecedented construction effort by pre-Columbian Native Americans. It has been estimated that from 2,000 to 6,000 people occupied Chaco Canyon during its heyday (Windes, 1984; Drager, 1976). One indication of Chaco’s regional importance is a network of roads that linked Chaco Canyon with other great houses and communities spread throughout a region covering at least 60,000 km2 (fig. 2). At the height of its cultural florescence in the 11th century, Chaco culture was characterized by the construction of monumental great houses (multistory, planned structures) that required millions of pieces of dressed sandstone and tens of thousands of roof beams. By 1130 A.D., Pueblo Bonito (fig. 3), one of 13 greathouses that occupied the canyon, was four stories tall and contained approximately 800 rooms (Neitzel, 2003). The size of Pueblo Bonito, its numerous large rooms, and the richness of its artifacts, which included caches of turquoise, copper bells, and finely crafted projectile points, suggest that it was a location where imported goods were amassed. Given the richness of its artifacts, some view Pueblo Bonito as having functioned primarily as an elite residence (Judge, 1989). Pueblo Bonito was occupied for at least 300 years; however, only 131 burials were found within the site, suggesting a sustained population averaging less than 100 people (Akins, 2003).

The oldest maize found in Pueblo Bonito probably was grown in an area at the base of the Chuska Mountains 80 kilometers (km) to the west. One maize sample (H-10648) found in Pueblo Bonito came from the San Juan or Animas river floodplains 90 km to the north. This study has demonstrated that maize was transported over considerable distances in pre-Columbian times.