A timeline of Chacoan history includes

Chaco Culture National Historical Park Chaco Culture National Historical Park is a United States National Historical Park in the American Southwest hosting a large concentration of pre-Columbian indigenous ruins of pueblos. The park is located in northwestern New Mexico, betwee ...

Aztec Ruins National Monument The Aztec Ruins National Monument in northwestern New Mexico, United States, consists of preserved structures constructed by the Pueblo Indians. The national monument lies on the western bank of the Animas River in Aztec, New Mexico, about n ...

, Twin Angels Pueblo, Casamero Pueblo, Kin Nizhoni, Pierre's Site, and

Halfway House A halfway house is a type of prison or institute intended to teach (or reteach) the necessary skills for people to re-integrate into society and better support and care for themselves. Halfway houses are typically either state sponsored for those ...

Paleo-Indian Period

; 11000 BC: First foragers?

Archaic Period

;6000 BC-800 BC: Hunter-gatherers

4th century CE

5th century

;490: Basketmaker farming begins

6th century

;500: Turquoise beads and pendants appear; offerings in great kivas (sites 29SJ423, Shabik' eshchee Village)

7th century

;600-800: La Plata Black-on-White ceramic ;700: Population of Chaco Canyon between 100 and 201 people Fagan, Brian M. (2005). ''Chaco Canyon''. Oxford University Press.

8th century

9th century

;800-900: Builders use piñon, juniper, and cottonwood trees that grew close by ;850-925: Large construction projects. ;875-1040: Red Mesa Black-on-White ceramics

10th century

;900-1150: Large buildings, mounds, roadways, great kivas, and tri-walled structures are built throughout the

San Juan Basin The San Juan Basin is a geologic structural basin located near the Four Corners region of the Southwestern United States. The basin covers 7,500 square miles and resides in northwestern New Mexico, southwestern Colorado, and parts of Utah a ...

. ;900-1125: Construction of Penasco Blanco ;900: Emergence of the Chaco

Anasazi The Ancestral Puebloans, also known as Ancestral Pueblo peoples or the Basketmaker-Pueblo culture, were an ancient Native American culture of Pueblo peoples spanning the present-day Four Corners region of the United States, comprising southea ...

;900:

Chetro Ketl 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 and was largely complete by 1075, with significant remodeli ...

pueblo begun ;900-1025:

Chaco Wash The Chaco Wash is an Arroyo (creek), arroyo (a periodic stream) cutting through Chaco Canyon, which is located in northwestern New Mexico on the Colorado Plateau. Another arroyo known as Escavada Wash is a tributary that feeds in from the northe ...

in erosional cycle and cut a paleo-channel.Durand, Stephen R. (Jan 2004). "Relation of "Bonito" Paleo-channels and Base-level Variations to Anasazi Occupation, Chaco Canyon, New Mexico." ''

American Antiquity ''American Antiquity'' is a professional journal published by Cambridge University Press for the Society for American Archaeology, an organization of professional archaeologists of the Americas. The journal is considered to be the flagship jour ...

'' 69.1: 191(1). ;925-1130: Stable environmental conditions favorable to dry farming throughout the

Colorado Plateau The Colorado Plateau is a physiographic and desert region of the Intermontane Plateaus, roughly centered on the Four Corners region of the Southwestern United States. This plateau covers an area of 336,700 km2 (130,000 mi2) within w ...

. Human populations also stable.Jorgensen, Joseph G. (Winter 2005). "Archaeological sociology in America's Southwest". ''

Journal of the Southwest The ''Journal of the Southwest'' is a quarterly peer review, peer-reviewed academic journal published quarterly by the Southwest Center, at the University of Arizona, with a focus on the Southwestern United States, American Southwest and adjacent ...

'' 47.4: 637(28). ;950:

Keet Seel Navajo National Monument is a national monument located within the northwest portion of the Navajo Nation territory in northern Arizona, which was established to preserve three well-preserved cliff dwellings of the Ancestral Puebloan people: Keet ...

, second largest cliff dwelling. is inhabited ;950: Nonlocal ponderosa is the dominant beam timber;

spruce A spruce is a tree of the genus ''Picea'' ( ), a genus of about 40 species of coniferous evergreen trees in the family Pinaceae, found in the northern temperate and boreal ecosystem, boreal (taiga) regions of the Northern hemisphere. ''Picea'' ...

and

fir Firs are evergreen coniferous trees belonging to the genus ''Abies'' () in the family Pinaceae. There are approximately 48–65 extant species, found on mountains throughout much of North and Central America, Eurasia, and North Africa. The genu ...

increase

11th century

;960-1020: Unpredictable rainfall. Little building at Pueblo Bonito ;1000: "Chaco phenomenon" acceleration of cultural development ;1000-1075:Great House construction, and roads expanded. The first usage of chocolate further than central Mexico was first used in ceramic cylinders for rituals. ;1000-1140: Escavada Black-on-White ceramics ;1025-1090: Depositional period during which time the paleo-channel was filling. There is some historical, anecdotal evidence that the inhabitants of Chaco Canyon may have constructed a dam at the west end of the canyon. ;1030:Chacoans seek trees at higher altitudes ;1040: Increased rainfall ;1040-1050: Building resumes at Old Bonito.

Pueblo Bonito Pueblo Bonito (Spanish for ''beautiful town'') is the largest and best-known great house in Chaco Culture National Historical Park, northern New Mexico. It was built by the Ancestral Puebloans who occupied the structure between AD 828 and 1126. ...

construction stage II ;1050-1070: Pueblo Bonito becomes more complex. Pueblo Bonito construction stage III ;1050: Imports of copper bells,

Macaw Macaws are a group of Neotropical parrot, New World parrots that are long-tailed and often colorful, in the Tribe (biology), tribe Arini (tribe), Arini. They are popular in aviculture or as companion parrots, although there are conservation con ...

s, and shells (origin unknown) ;1054: ~July 4 - Cliff painting near Penasco Blanco consisting of three symbols: a large star, a crescent moon, and a handprint, may portray the sighting of

SN 1054 SN 1054, the Crab Supernova, is a supernova that was first observed on , and remained visible until . The event was recorded in contemporary Chinese astronomy, and references to it are also found in a later (13th-century) Japanese document and ...

, the Crab Nebula

supernova A supernova (: supernovae or supernovas) is a powerful and luminous explosion of a star. A supernova occurs during the last stellar evolution, evolutionary stages of a massive star, or when a white dwarf is triggered into runaway nuclear fusion ...

. ;1064, 1066:

Sunset Crater Sunset Crater is a cinder cone located north of Flagstaff in the U.S. state of Arizona. The crater is within the Sunset Crater Volcano National Monument. Sunset Crater is the youngest in a string of volcanoes (the San Francisco volcanic fie ...

volcanic eruptions; volcanic debris blankets Jemez Mountains and Bandelier area. ;1080-1100: Great North Road construction.Lekson 1999 ;1080: Salmon Ruin established. ;1080: Construction of

Pueblo Alto Pueblo Alto ("High Village" in Spanish) is an Ancestral Puebloan The Ancestral Puebloans, also known as Ancestral Pueblo peoples or the Basketmaker-Pueblo culture, were an ancient Native American culture of Pueblo peoples spanning the pr ...

begins. ;1090: Drought

12th century

;1075-1123:

constructed at Chaco. ;?: Five astronomical observatories are built ;1100: Peak of Chaco culture. ;1100-1104: Tree felling at Pueblo del Arroyo ;1106-1125:

Aztec Ruins The Aztec Ruins National Monument in northwestern New Mexico, United States, consists of preserved structures constructed by the Pueblo Indians. The national monument lies on the western bank of the Animas River in Aztec, New Mexico, about nor ...

built. ;1130: Pueblo Bonito is four stories tall and contains 800 rooms ;1130-1180: Fifty-year drought in the Southwest. Rain and snow cease to fall. Alluvial groundwater declines, floodplain erosion occurs. Dry-farming zone reduced, crop production potential decreased. Severe arroyo cutting and depression of alluvial groundwater. Severe environmental stress. ;1140–1150: Collapse of the Ancestral Puebloan culture at Chaco Canyon. ;1150: Great Houses empty ;1180:

erupts for the second time.

13th century

14th century

15th century

16th century

;1539:

Marcos de Niza Marcos de Niza, Order of Friars Minor, OFM (or Marco da Nizza; 25 March 1558) was a Franciscan friar and missionary from the city of Nice in the Duchy of Savoy. Marcos led the first Spanish expedition to explore what is now the American Southw ...

erroneously describes the pueblo of Háwikuh as the

Seven Cities of Gold The myth of the Seven Cities of Gold, also known as the Seven Cities of Cíbola (), was popular in the 16th century and later featured in several works of popular culture. According to legend, the seven cities of gold referred to Aztec mythology ...

17th century

;1680-1692: The

Pueblo Revolt The Pueblo Revolt of 1680, also known as Popé, Popé's Rebellion or Po'pay's Rebellion, was an uprising of most of the Indigenous Pueblo people against the Spanish Empire, Spanish colonizers in the province of Santa Fe de Nuevo México, larger t ...

of the Pueblo people against Spanish colonists in the New Spain province. ;1774: Don

Bernardo de Miera y Pacheco Bernardo de Miera y Pacheco (4 August 1713 – 4 or 11 April 1785) was "perhaps the most prolific and important cartographer of New Spain" as well as an artist, particularly as a ''Santo (art), Santero'' (wood-carver of religious images). He h ...

identifies the Chaco Canyon area as "Chaca" on a map. The term, a Spanish translation of a Navajo word, is thought to be the origin for "Chacra Mesa" and "Chaco".

18th century

19th century

;1844:

Josiah Gregg Josiah Gregg (19 July 1806 – 25 February 1850) was an American merchant, explorer, naturalist, and author of '' Commerce of the Prairies'', about the American Southwest and parts of northern Mexico. He collected many previously undescribed pla ...

refers to the Chaco pueblos in his book ''Commerce of the Prairies'', making its first appearance in popular culture. ;1849: Lt. James H. Simpson leads the Washington Expedition, a military reconnaissance team which surveys

Navajo The Navajo or Diné are an Indigenous people of the Southwestern United States. Their traditional language is Diné bizaad, a Southern Athabascan language. The states with the largest Diné populations are Arizona (140,263) and New Mexico (1 ...

lands and records cultural sites in Chaco Canyon. Illustrations created by the Kern brothers are included in a government report. ;1877: Artist and photographer

William Henry Jackson William Henry Jackson (April 4, 1843 – June 30, 1942) was an American photographer, American Civil War, Civil War veteran, painter, and an explorer famous for his images of the American West. He was a great-great nephew of Samuel Wilson, t ...

participates in the

Hayden Survey Ferdinand Vandeveer Hayden (September 7, 1829 – December 22, 1887) was an American geologist noted for his pioneering surveying expeditions of the Rocky Mountains in the late 19th century. He was also a physician who served with the Union A ...

of the Western United States, producing maps of Chaco Canyon, but no photographs due to technical problems. ;1888:

Richard Wetherill Richard Wetherill (1858–1910), a member of a Colorado ranching family, was an amateur archaeologist who discovered, researched and excavated sites associated with the Ancient Pueblo People. He is credited with the rediscovery of Cliff Pal ...

and Charlie Mason find the

Cliff Palace Cliff Palace is the largest cliff dwelling in North America. The structure built by the Ancestral Puebloans is located in Mesa Verde National Park in their former homeland region. The cliff dwelling and park are in Montezuma County, in the s ...

, Spruce Tree House and

Square Tower House In geometry, a square is a regular quadrilateral. It has four straight sides of equal length and four equal angles. Squares are special cases of rectangles, which have four equal angles, and of rhombuses, which have four equal sides. As with all ...

. : Chaco Canyon is surveyed and photographed by Victor and Cosmos Mindeleff of the

Bureau of American Ethnology The Bureau of American Ethnology (or BAE, originally, Bureau of Ethnology) was established in 1879 by an act of Congress for the purpose of transferring archives, records and materials relating to the Indians of North America from the Departme ...

;1896:

begins excavating Chaco Canyon ;1896-1899: George H. Pepper from the

American Museum of Natural History The American Museum of Natural History (AMNH) is a natural history museum on the Upper West Side of Manhattan in New York City. Located in Theodore Roosevelt Park, across the street from Central Park, the museum complex comprises 21 interconn ...

leads the Hyde Exploring Expedition in excavating

20th century

;1901: General Land Office special agent S. J. Holsinger recommends creating a national park to preserve archaeological sites in Chaco Canyon ;1907: Chaco Canyon National Monument is established. ;1928-1929: American astronomer and University of Arizona professor A. E. Douglass participates in a National Geographic Society research project exploring Chaco Canyon. Using his newly invented technique of

dendrochronology Dendrochronology (or tree-ring dating) is the scientific method of chronological dating, dating tree rings (also called growth rings) to the exact year they were formed in a tree. As well as dating them, this can give data for dendroclimatology, ...

, Douglass dates Chetro Ketl and dozens of Chacoan sites : Expedition under Neil Merton Judd to collect dendrochronological specimens to date habitation of Chaco Canyon ;1937: A

Civilian Conservation Corps The Civilian Conservation Corps (CCC) was a voluntary government unemployment, work relief program that ran from 1933 to 1942 in the United States for unemployed, unmarried men ages 18–25 and eventually expanded to ages 17–28. The CCC was ...

stonemason Stonemasonry or stonecraft is the creation of buildings, structures, and sculpture using stone as the primary material. Stonemasonry is the craft of shaping and arranging stones, often together with mortar and even the ancient lime mortar ...

s repairs Chacoan buildings in Chaco Canyon. A previous group built soil conservation devices, planted trees, and improved roads and trails. ;1941: Heavy rains cause Threatening Rock to fall, destroying ~60 rooms at

. ;1960: Floors excavated at Una Vida ;1971-1982: The Chaco Project, conducted by the

National Park Service The National Park Service (NPS) is an List of federal agencies in the United States, agency of the Federal government of the United States, United States federal government, within the US Department of the Interior. The service manages all List ...

and the

University of New Mexico The University of New Mexico (UNM; ) is a public research university in Albuquerque, New Mexico, United States. Founded in 1889 by the New Mexico Territorial Legislature, it is the state's second oldest university, a flagship university in th ...

, surveys and excavates Chaco Canyon ;1976-1978: Fourteen rooms at

excavated by the Chaco Project ;1980: Chaco Canyon National Monument is renamed Chaco Culture National Historical Park with 13,000 acres (53 km²) added. The Chaco Culture Archaeological Protection Site program is created to protect Chacoan sites. ;1982:

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

's Thermal Infrared Multispectral Scanner (TIMS) detects over 200 miles of a prehistoric (AD 900 or 1000) road system in Chaco Canyon, as well as walls, buildings, and agricultural fields. ;1983: Dean and Warren estimate 200,000 trees were used to build great houses. ;1987: Chaco Culture National Historical Park is designated a

UNESCO World Heritage Site World Heritage Sites are landmarks and areas with legal protection under an treaty, international treaty administered by UNESCO for having cultural, historical, or scientific significance. The sites are judged to contain "cultural and natural ...

21st century

;2001: Two-thirds of large roof timbers traced to Chuska Mountains and one-third to San Mateo Mountains.

References

{{DEFAULTSORT:Timeline Of Chacoan History Chacoan Chacoan Chaco Canyon