The deterioration of the Pueblo Bonito Great House in the Chaco Culture National Historical Park, New Mexico, USA.

Pueblo Bonito is the iconic pre- Columbian structure in Chaco Culture National Historical Park, a World Heritage Site in northwestern New Mexico, USA. The structure, dating to about 850-1150 Current Era, and built of quarried sandstones, wooden timbers and a mud mortar, has been the subject of archaeological investigations for over a century. The present study is based on the examination of historical photographs of Pueblo Bonito dating from 1887 to the 1920s.

Could the Ancestral Puebloans of Chaco Canyon, New Mexico, Have Depended on a Groundwater Ecosystem?

A thousand years ago, a population of Ancestral Puebloans occupied a high desert canyon in northwestern New Mexico, USA, where precipitation was limited and surface water scarce. Geological conditions, however, seem favorable for the production of a large Hypocrene springs system near the south canyon walls sufficient to have produced a groundwater ecosystem favorable for agriculture, tree growth, and human occupancy. A human-induced ecological impact is suggested as contributing to the dewatering of the springs, eventually reducing local agricultural production and, presumably, the suitability of Chaco Canyon for human occupancy.