Pueblo Bonito is the largest of 20+ towns in Chaco Canyon, NM that was built by ancient Pueblo people mainly after A.D. 1030. Chaco Canyon is along the San Juan Basin in NW New Mexico. The Navajo new of the site and called it tse biyaa anii'ahi, leaning rock gap and the people, Anasazi meaning 'ancient enemy people'. The Spanish named the prehistoric site Pueblo Bonito, 'pretty village' and explored the area as early as  A.D.1598.

Lt. James Simpson was the first Anglo-American guided there by Carravahal (San Juan Pueblo) in 1849. The first excavation was conducted by Richard Wetherill and George Pepper of the Museum of Natural History beginning in 1896. Subsequently, Wetherill, a local rancher and amateur archaeologist set up a trading post near the ruins.

Some of these early 'expeditions' were essentially sponsored pot hunting operations. The Hyde Expedition shipped a full freight car of artifacts to New York  in 1896 alone. In fact such large scale operations generated concern that led to the passage (drafted by E. Hewett) of the Federal Antiquities Act on June 8, 1906.

Subsequent work between 1921 - 1969 was conducted by students with minimal publication of results. However, excavations from 1969-1980's resulted in the major publications on Chaco Canyon. Also, in the 1980's remote sensing, Thermal Infrared Multispectral Scanner (TIMS) was employed by NASA, and revealed a complex network of roads radiating in and out of Chaco Canyon. These roads were exceptionally linear and about 15'-20' wide. Finally, a number of scientists have surveyed Chaco Canyon and Pueblo Bonito in terms of archaeoastronomy alignments of buildings, roads, and rock art.

II. Cultural Context

Pueblo Bonito is a large 'D' shaped town constructed of a core-and- veneer masonry  reaching 5 stories in some areas forming 800 rooms and 37 kivas.

As the largest structure in Chaco Canyon, Pueblo Bonito may have been a center of activity and a lack of refuse indicates that people may have not actually lived in the town on a permanent basis. The town was built between A.D. 850 and 1130 spanning Pueblo I -III periods of Anasazi culture. Construction was probably in about three phases with the back wall completed by A.D. 1050. Since timber was used in the ceilings, dendronchronology  (tree-ring dating) has provided dates for the different phases of construction.

Turquoise was an important commodity at Pueblo Bonito and a considerable trade network was conducted with the Toltec Empire in Tollan/Tula. This turquoise was mined in Cerillos and processed in Chaco Canyon into small squares or beads which were traded in all directions. However, Tollan was the most lucrative trading partner and brought macaws, which were valued for their brilliant feathers. Black and white pottery with geometric designs was prevalent at Chaco Canyon and in some areas great caches of broken pottery, projectile points and turquoise were found inside and outside the canyon especially along the great northern road. Some scholars also feel that Pueblo Bonito and other major towns represent architectural exercises of spatial cosmological alignments.

By A.D. 1130 building at Pueblo Bonito had ceased and people began to migrate to Mesa Verde. Finally, by A.D. 1300 people moved out of the four corner's area and moved again to the Rio Grande and Colorado Plateau to become today's modern Pueblo communities.

In 1907 Chaco Canyon and Pueblo Bonito were designated as a National Monument in conjunction with the American Antiquities Act of 1906. However, the canyon location was remote and access was difficult. It was not until 1946 that open range grazing was harnessed with fencing. Only in 1980 did the area become Chaco Culture National Historical Park and a visitor's center was built in 1980's. In 1987  Chaco Canyon became a World Heritage Site under UNESCO. Today access is via a paved road and many more visitors are able to see the many ruins in Chaco Canyon, including Pueblo Bonito.