An ancient cliff dwelling civilization arose as early as 1500 B.C.
Their descendants are today�s Pueblo Indians, such as the Hopi and the Zuni, who live in 20 communities along the Rio Grande, in New Mexico, and in northern Arizona.
During the 10th and 11th centuries, ChacoCanyon, in western New Mexico, was the cultural center of the Anasazi homeland, an area roughly corresponding to the Four Corners region where Utah, Colorado, Arizona and New Mexico meet.
This 30,000-square-mile landscape of sandstone canyons, buttes and mesas was populated by as many as 30,000 people.
The Anasazi built magnificent villages such as ChacoCanyon�s Pueblo Bonito, a tenth-century complex that was as many as five stories tall and contained about 800 rooms.
The people laid a 400-mile network of roads, some of them 30 feet wide, across deserts and canyons. And into their architecture they built sophisticated astronomical observatories.
Little is known about the Anasazi way of life except for clues left in the form of cave art. A recently discovered site called Penasco Blanco shows a depiction on a cave wall of what must be a supernova explosion.
The relative orientations of the crescent moon and the star make it very likely that this is a recording of the supernova which created the Crab Nebula in 1054 A.D.
This supernova, which would have been about five times brighter than Venus for about three weeks, is also verifiable by Chinese astronomical records.
Another very interesting site is called the Anasazi sun dagger. It is a spiral design traced into a cave wall, and during midsummer, midwinter, and the equinoxes it is perfectly bisected or surrounded by daggers of sunlight which enter the specially placed windows.
The Anasazi also built a solar observatory called Hovenweep Castle at Four Corners. All of this evidence points to the fact that the Anasazi were quite experienced sky-watchers, as are their probable descendents, the Pueblo Indians.
The Anasazi engineered road building. The Chaco Road had astronomical implications, certainly, and played an important role in Chaco culture, as it is visible in the north-south axis alignment of many ceremonial structures.
The main buildings at Pueblo Bonito, for example, are arranged according to this direction and probably served as central places for ceremonial journeys across the landscape.