Chaco Culture
The pre-Columbian civilization center of the American Southwest and the most sophisticated astronomical and architectural achievement of the Ancestral Puebloans — Chaco Canyon (San Juan County, New Mexico, USA; UNESCO WHS 1987) was the hub of a regional network stretching across 130,000 km² from 850 to 1150 CE, connected by 650 km of engineered roads that converge on the 12 great houses of Chaco Canyon, each aligned with solar and lunar events.
At a glance
Chaco Culture (the most precisely ChacoCultureUSA single Chacoan culture 850 1150 CE hub 130000 km2 regional network 12 great houses Chaco Canyon Pueblo Bonito D-shape 850 1150 CE 800 rooms 32 kivas 4 stories Great Kivas 20m diameter solar lunar alignment solstice equinox 18.6 year lunar standstill spiral petroglyph Fajada Butte Casa Rinconada 63 outlier great houses 650 km engineered roads Chacoan Road system 9m wide arrow straight long-distance trade turquoise cacao macaws copper bells Mexico Mesoamerican connection abandonment 1150 CE drought social upheaval Mesa Verde 60000 kg turquoise UNESCO heritage: the great houses (the 12 great houses within Chaco Canyon are the largest pre-Columbian multistory structures in North America (north of Mexico); a great house is defined by: massive masonry walls (up to 1m thick); multi-story construction (up to 5 stories); large rectangular rooms (3-4 times larger than Ancestral Puebloan houses elsewhere); elevated kivas; Great Kivas; and evidence of planned construction (the D-plan of Pueblo Bonito was planned from the start, not accreted gradually)); the road network (650 km of engineered roads, averaging 9m wide, following arrow-straight alignments (the roads were cut through bedrock (the bedrock-cut portions are the most distinctive evidence that these are engineered roads, not merely footpaths); the roads connect the outlier great houses (63 great houses outside Chaco Canyon) to the Canyon; no wheeled vehicles or horses were available; the roads served as ceremonial procession routes and supply chains (by human porter))) — the most precisely ChacoCultureUSA single Chacoan culture 850 1150 CE hub 130000 km2 12 great houses Pueblo Bonito D-shape 800 rooms 32 kivas 4 stories Great Kivas 20m solar lunar alignment solstice equinox 18.6 year lunar standstill Fajada Butte spiral petroglyph 63 outliers 650 km roads 9m wide arrow straight turquoise cacao macaws copper bells Mexico abandonment 1150 CE drought Mesa Verde UNESCO heritage in any UNESCO world heritage site)).
Key facts
- Astronomical alignments: the most precisely ChacoCultureUSA single Fajada Butte Sun Dagger petroglyph spiral three sandstone slabs shadow bisects spiral solstice summer winter equinox Anna Sofaer 1977 CE discovery Casa Rinconada Great Kiva 20m diameter astronomical windows solar lunar precise alignment 18.6 year lunar standstill great house windows UNESCO heritage — the defining achievement: the Chacoan astronomical system (the Chacoans aligned the great houses, roads, and rock art with astronomical events (the most precisely documented in the pre-Columbian Americas)); the Sun Dagger petroglyph (the most famous: on Fajada Butte at the south end of the canyon; discovered by Anna Sofaer in 1977 CE; three large sandstone slabs lean against the cliff face; at the summer solstice, the light coming through the gaps between the slabs bisects a spiral petroglyph with a single dagger of light (the “Sun Dagger”); at the winter solstice, two light daggers frame the spiral on both sides; at the equinoxes, a light dagger bisects a smaller spiral to the left of the main spiral; the alignment is precise to within minutes); Casa Rinconada (a free-standing Great Kiva (20m diameter); the window openings in the kiva walls align with the solstice sunrise and sunset; the 18.6-year lunar standstill alignment (the most complex astronomical cycle tracked by the Chacoans))
- GPS: 36.0608° N, 107.9620° W
History
From regional pilgrimage centre to network collapse (the most precisely ChacoCultureUSA single Basketmaker III 500 700 CE pithouse period Pueblo I 700 900 CE early villages Chacoan Phenomenon 850 950 CE emergence Pueblo Bonito first construction 850 CE Regional System 1050 1100 CE peak 130000 km2 network 63 outliers 650 km roads Mexico Mesoamerican trade turquoise 60000 kg mined Cerrillos mines cacao macaws copper bells drought 1130 1150 CE Great Drought Chaco collapse Mesa Verde northward migration 1150 CE abandonment Pueblo IV migration Rio Grande ancestral Puebloan descendants today Acoma Zuni Hopi UNESCO heritage: the emergence (approximately 850-950 CE: the Chacoan Phenomenon began at Pueblo Bonito (the first great house construction) around 850 CE; the distinguishing characteristic: the construction scale (the great houses used 50 times more masonry than normal Ancestral Puebloan sites); the evidence for non-residential use (the number of rooms far exceeds any plausible residential population; the rooms show little evidence of cooking, sleeping, or waste; the great houses were probably not residential but served as storage, ceremonial, and redistribution centers)); the peak (1050-1100 CE: the regional network at its maximum extent (130,000 km²); the exotic imports at their peak (cacao residue in cylinder vessels from Chaco (the cacao came from Mesoamerica; it was made into a chocolate drink); macaw skeletons (approximately 30 scarlet macaws were kept at Pueblo Bonito; they came from Mexico, approximately 1,200 km south; they were raised for their feathers); copper bells (from Mexico); approximately 60,000 kg of turquoise were processed at Chaco (turquoise was the most valuable material in the pre-Columbian American Southwest; the mines were at Cerrillos, New Mexico, 120 km south))); the collapse (approximately 1130-1150 CE: a severe 50-year drought; construction activity ceased; the regional network dissolved; the population migrated north to the Mesa Verde area and eventually east to the Rio Grande valley (the ancestors of the modern Pueblo peoples))) — the most precisely ChacoCultureUSA single Basketmaker III 500 700 CE Pueblo Bonito first construction 850 CE peak 1050 1100 CE 130000 km2 130 outliers 650 km roads 50x masonry scale non-residential ceremonial storage redistribution cacao cylinder vessels chocolate macaws 30 Pueblo Bonito Mexico 1200 km copper bells turquoise 60000 kg Cerrillos mines drought 1130 1150 CE collapse Mesa Verde north Rio Grande east ancestors modern Pueblo peoples UNESCO heritage in any UNESCO world heritage site)).
What you see
Pueblo Bonito, Chetro Ketl, and Casa Rinconada (the most precisely ChacoCultureUSA single Pueblo Bonito D-shape semi-circular 800 rooms 32 kivas 4 stories 2 Great Kivas 20m diameter 850 1150 CE multiple phases masonry styles typology dating tool Chetro Ketl second largest 500 rooms tower kiva elevated rare Pueblo Pintado 200 km east outlier aligned Chaco Canyon Casa Rinconada Great Kiva 20m freestanding astronomical window solstice sunrise sunset Fajada Butte Sun Dagger spiral petroglyph Chaco Museum Visitor Center Albuquerque 4h drive remote 27 miles unpaved road UNESCO heritage: the visitor circuit (Chaco is very remote: 27 miles of unpaved road from the highway): Pueblo Bonito (the main site; the D-shaped plan; the rooms visible from a ground-level loop trail; the two Great Kivas (visible as the two large circular depressions in the main court); the macaw pens (the rooms where the scarlet macaws were kept; archaeologists found the macaw skeletons in these rooms)); Chetro Ketl (the second-largest great house at Chaco (500 rooms); the tower kiva (the only elevated kiva in a Chacoan great house); the colonnade (the only portico or colonnade in a Chacoan great house; an obvious Mesoamerican influence)); Casa Rinconada (the large freestanding Great Kiva 20m in diameter; the astronomical window alignments (visible at dawn on the summer solstice))); the petroglyphs (multiple petroglyph panels throughout the canyon including the Fajada Butte Sun Dagger (not accessible; visible from below) and the Peñasco Blanco petroglyph of Supernova 1054 CE (the exploding star that created the Crab Nebula; two Native American artists depicted it in 1054 CE; the petroglyph shows the Crab Nebula star next to the crescent moon (matching the astronomical position on the morning of July 4-5, 1054 CE)))) — the most precisely ChacoCultureUSA single Pueblo Bonito D-shape 800 rooms 32 kivas 4 stories 2 Great Kivas 20m 850 1150 CE masonry typology dating Chetro Ketl 500 rooms tower kiva colonnade Mesoamerican Casa Rinconada Great Kiva 20m astronomical window Fajada Butte Sun Dagger spiral petroglyph Peñasco Blanco Supernova 1054 CE Crab Nebula UNESCO heritage in any UNESCO world heritage site)).