Chaco Canyon

Chaco Canyon is a dry gorge in New Mexico where almost nothing grows. In it stand the largest buildings raised in North America before the nineteenth century, and nobody is certain why they are there.

The great houses

Pueblo Bonito is the largest: over six hundred rooms in up to five storeys, built in a D-shape around an open plaza. The walls are core-and-veneer — two skins of dressed sandstone with rubble between — and they still carry their own weight a thousand years on.

Around it stood twelve other great houses in the canyon itself, and over two hundred across the surrounding country.

Timeline

850

construction of Pueblo Bonito begins

1020

the great building period; the great houses take their form

1054

the supernova that may be depicted on a cliff face here

1085

Chetro Ketl is completed; the road system is extended

1130

fifty years of drought begin

1140

building stops

1200

the canyon is largely abandoned

1250

the people have moved to Mesa Verde and the Rio Grande valley

The sum that does not add up

The canyon could not feed the population its buildings imply. The soil is thin, rainfall is 22 centimetres a year, and the growing season is short.

Everything had to be brought in. Over two hundred thousand roof beams were cut in mountain forests up to eighty kilometres away, carried without draught animals and without wheels. Charcoal and strontium analysis has traced them to particular ranges. Pottery, maize and even drinking water came from outside.

The roads

Roads radiate from the canyon — over six hundred kilometres of them — up to nine metres wide, with steps cut into rock where they meet an escarpment. They run straight, without curving around obstacles.

A people without wheels and without draught animals has no practical use for a nine-metre road. Interpretations therefore run to the ceremonial: pilgrimage routes, or lines binding outposts to the centre symbolically.

The macaws

The great houses have yielded skeletons of scarlet macaws. The nearest population lived over two thousand kilometres south, in tropical Mexico. The birds were carried alive, and some were hatched in the canyon. Together with cacao residue in the pottery, this shows a connection southward that was living and regular.

The descendants

Chaco was not destroyed. When the drought came the people moved — to Mesa Verde first, later to the Rio Grande pueblos and to Hopi and Zuni. Those communities endure. For them Chaco is not a ruin but an ancestral place, and several of them object to both excavation and tourism there.