University of Colorado archaeologist Stephen Lekson was wrestling with archaeological maps a few years back, trying to align a map of northern Mexico with one of the southwestern United States, when he noticed something striking.
The three biggest and most important U.S. and Mexican archaeological ruins in the region stood in a laser-straight line that stretched across 460 miles of mountains, canyons and desert.
Not just any line. Casas Grandes -- a 600-year-old adobe ruin in northern Chihuahua, Mexico -- was built on the exact same north-south line of longitude as both Chaco Canyon and Aztec Ruins, two slightly older sandstone ruins to the north in northwestern New Mexico.
And these were not just any ruins. Each of the three sites had been the largest, most important trading and spiritual center in its region. Archaeologists found monumental structures, turquoise beads, copper bells and bird feathers imported 1,000 miles from Central America. Early research had suggested the cultures had flourished in the 12th and 13th centuries, and then vanished, well before Christopher Columbus brought Spanish conquerors to the Americas.
"It got my attention," Lekson says. But he kept his mouth shut about it.
"At the time, archaeo-astronomers were lining up Chaco with anything [in the sky] that didn't move, and a lot of stuff that did," he says. It was a time when New Age mystics and others were producing reams of literature arguing that ancient people in Africa or the Near East had been given astronomical knowledge by beings from Sirius, the Pleiades or other star systems.
In that atmosphere, his own discovery "seemed like Looney Tunes," he says. "I suppressed it."
But then something happened to tie the three extraordinary ruins together in a new way, and give Lekson's discovery potential new significance.
In 1993, tree ring expert Jeffrey Dean of the University of Arizona and archaeologist John Ravesloot of the Gila River Indian Reservation published new estimates for the age of Casas Grandes, based on a redating of tree rings on the adobe ruin's surviving timbers.
Casas Grandes turned out to be much younger than Chaco, not contemporaneous as had been thought. The new dates, combined with a re-evaluation of artifacts collected in the region for decades, convinced Lekson that the three sites had actually flourished and faded -- one after the other -- between A.D. 850 and 1500. He now believes they served as the successive centers of a single, evolving regional culture and economy that acted across a stage far larger than anyone imagined.
In a talk last month in Baltimore, Lekson argued that the people of Aztec Ruins, and later Casas Grandes, established their political or religious legitimacy by aligning their structures physically with Chaco Canyon.
It could be coincidence, he admitted. But what are the chances that three unique sites, each the largest in the region in its day, would fall by mere coincidence along the same line, much less a precise meridian of longitude?
The scientific evidence -- tree ring dates, architecture and artifacts -- suggests the culture was first centered on the structures at Chaco Canyon, begun around 850. The largest building, Pueblo Bonito, was 500 feet long and originally five stories high, suggesting that Chaco was a ceremonial center for a ruling or religious elite.
Chaco faded as a political or religious center between 1110 and 1125, perhaps due to a long drought revealed in the tree rings. At the same time, large buildings went up at Aztec Ruins, beside a year-round river 60 miles north. (Misnamed by white settlers, the ruins have nothing to do with the Aztec culture of Mexico.)
Then, sometime between 1250 and 1275, during another long drought, Aztec was abandoned, along with nearby communities such as the Mesa Verde cliff dwellings. And far to the south in Mexico, Casas Grandes began to flourish, producing artifacts and architecture reminiscent of Chaco and Aztec.
Lekson said the stories of New Mexico's Pueblo Indians, who claim descent from these "Anasazi" ("ancient ones" in Navajo), say some people from Chaco and Aztec stayed to found pueblos such as those at Acoma and Zuni. Others moved far to the south to raise macaws. (The colorful birds, native to jungles 1,000 miles south in Mexico, were raised for their prized feathers. Their remains have been found at Aztec and Chaco, and breeding pens were found at Casas Grandes.)
Today's Pueblo people still revere Chaco Canyon as their point of origin. Lekson believes the Anasazi "legitimize their new centers by making reference to the old in this physical act of alignment."
He likens them to authoritarian leaders, such as the medieval Holy Roman emperors, the Russian czars and the German kaisers, who legitimized their authority through references to ancient Rome and the Caesars.
This notion of symbolism in the north-south alignment is reinforced by the "North Road," an ancient roadway archaeologists discovered running due north from Chaco to Aztec.
It is no winding wilderness path. Thirty feet wide, it runs nearly arrow-straight for 60 miles. It crosses plains, scales ridges and canyons on hand-cut steps, wandering less than a half-mile from the meridian line at 107 degrees, 57 minutes, 30 seconds west longitude.
Nor was it a highway for trade. "They didn't need a road in an economy where everything moved on human backs," Lekson said.
Lekson has not yet found a similar road linking Chaco to Casas Grandes, across 400 miles of desert, mountains and canyons. But he has little doubt that the Anasazi could have surveyed the line without modern tools.
Using the sun's daily arc to establish east and west, the Indians could have easily found north and south, and then extended the line with months, or years, of careful sightings.
Mountain ridges would block their line of sight a dozen times, repeatedly forcing them to re-establish north and south. But that would have allowed the inevitable line-of-sight errors to cancel each other out. Across 400 miles, the computer predicted an error of about one kilometer -- 0.6 miles.
Casas Grandes proved to be east of the meridian established by the North Road from Chaco to Aztec -- by one kilometer.
Why the Anasazi might build their centers along a north-south line is a puzzle. Unlike the seasonal points where the sun rises or sets, the meridian would not help them time the planting or harvesting of their corn.
"It doesn't do anything for you," Lekson says. "This north-south business is totally arbitrary. It's a nice human decision."
Maybe not totally arbitrary. North and south would be obvious to anyone living beneath the starry skies of the desert Southwest. It is the axis around which the night sky revolves, putting any observer's location at the apparent "center" of the universe.
This "cardinality" -- alignment with the main, or "cardinal" compass points -- is unique in the Southwest, Lekson says. But more importantly, if he's right, his ideas create a new cultural geography stretching from northwestern New Mexico south to Chihuahua.
Pub Date: 11/18/96