page_title: Chetro Ketl
section_title: Deterioration and preservation
hierarchical_section_title: Chetro Ketl / Deterioration and preservation
caption_attribution_description: English: Chetro Ketl from the mesa top
context_page_description: Chetro Ketl is an Ancestral Puebloan great house and archeological site located in Chaco Culture National Historical Park, New Mexico, United States. Construction on Chetro Ketl began c. 990 and was largely complete by 1075, with significant remodeling occurring in the early and mid-1110s. Following the onset of a severe drought, most Chacoans emigrated from the canyon by 1140; by 1250 Chetro Ketl's last inhabitants had vacated the structure.
  The great house was rediscovered in 1823 by the Mexican governor of New Mexico, José Antonio Vizcarra, and in 1849 Lieutenant James Simpson of the United States Army Corps of Engineers documented the major ruins in Chaco Canyon. Edgar L. Hewett, the director of the first archeological field school in the canyon, conducted excavations of Chetro Ketl during 1920 and 1921, and again between 1929 and 1935.
  Chaco scholars estimate that it required more than 500,000 man-hours, 26,000 trees, and 50 million sandstone blocks to erect Chetro Ketl. The great house is a D-shaped structure; its east wall is 280 feet long, and the north wall is more than 450 feet; the perimeter is 1,540 feet, and the diameter of the great kiva is 62.5 feet.
context_section_description: Lekson and McKenna note that following the rediscovery of Chetro Ketl in the early 19th century, the building's "pace of dissolution increased alarmingly ... [it] has deteriorated at a faster rate over the last century and a half than in the previous six." Chetro Ketl's wooden elements have proven especially vulnerable in a region that lacks timber, with soldiers, cattlemen, and transients scavenging them from the structure. The rear balcony was present in 1901, but by 1921 the beams had been removed by people scouring the canyon for wood. The process of uncovering beams during excavation has further hastened their deterioration. Chaco Wash, which deepens and widens during summer rain showers, also threatens the canyon's ruins. The once prominent refuse mound has been all but destroyed by repeated trenching and by diverting arroyos near Chetro Ketl. Treasure hunting, livestock grazing, and early National Park Service stabilization efforts also contributed to the degradation of the structure, as have deep excavations that left Chaco Wash prone to flooding. Archeology was responsible for the catastrophic effects of a 1947 flood that destroyed the walls of twenty rooms and collapsed 40 feet (12 m) of the north wall. It also toppled Chetro Ketl's tallest remnants.
  During the late 1980s, a reburial program was undertaken at Chetro Ketl that sought to preserve the structure's original timbers by backfilling portions of the site with soil. Because only a thin layer of overburden was applied, specialized geosynthetic materials were added to help keep the area dry. The program also developed techniques that facilitate the sampling of ancient wood for assessment of deterioration. Lekson and McKenna note, "the visible building is far from pristine. Most walls have undergone generations of structural and cosmetic treatment ... Chetro Ketl is an artifact deteriorating before our eyes. If the reader is inspired to questions that cannot be answered by the present study, be advised that Chetro Ketl's ability to answer in detail is slowly, but surely, disappearing."
caption: Chetro Ketl from the mesa top, facing west (2008)
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