Chaco Canyon is an amazing place of ancient settlements in a unique Great House system connected by a sophisticated network of roads.
We had planned to visit Chaco Canyon on our own but discovered late on that we were not allowed to drive our rental car on dirt roads. We were extremely lucky that there was a small tour scheduled which we were able to add ourselves to on the morning of departure. The guide was the curator of the Salmon Ruins Museum, she only takes 4 people max at very intermittent intervals and there were two people who had arranged to be taken to Chaco. After a mad dash to get ourselves some lunch to take along we set off, after paying the $200 fee per person.
Back down the 550 for 35 miles then onto the road for Chaco itself which is fine to begin with then becomes gravel and the final part is dirt before arriving in the park. The guide said that almost every time she goes in there will be a broken down car at the side of the road. We were fortunate that the unpaved roads had recently been graded but it was still a very bumpy ride.
The Chaco Culture National Historic Park is a UNESCO World Heritage Centre which protects the impressive remains of Ancestral Puebloan settlements that developed here from around 850 AD.
On the face of it this is not a very attractive site to build a home. The valley is arid with a harsh climate and very few water sources. However, the communities grew to be home to thousands of Chacoans who developed a distinctive Chacoan culture.
Chaco was the centre of a vast trade network, importing goods from as far as Mexico such as tropical bird feathers, copper bells and seashells. Aerial photography has revealed a network of roads connecting Chaco to some 150 outlying settlements, farms and forests where timber was harvested. The roads often climbed over cliffs and mesas rather than going around them, much the same as Roman roads, and were up to 30 feet wide. The Chacoans had no wheeled carts and no pack animals so why such wide roads?
We stopped just before the visitor centre to see Fajada Butte, sacred to the indigenous peoples of the region. On top it has an astronomical device, spiral petroglyphs carved close to three upright boulders such that at special astronomical times - summer and winter solstice, spring and autumn equinox - daggers of light are cast onto the spiral through the gaps between the boulders.
Like many ancient agricultural people, the Chacoans had sophisticated knowledge of the sun's movements across the sky throughout the year which enabled them to plan their agricultural and ceremonial activities.
We first stopped at Una Vida. The Chacoans built this "Great House" in the mid 800s making it one of the earliest in the valley. Building continued up to around 1100 AD. The walls were made from rock sheared from the cliffs and were quite rough. The Chacoans learnt to shape the blocks so that they fit together more smoothly with minimal use of mud mortar which involved the use of precious water. The walls are beautiful, smooth and vertical. The walls are beautiful - smooth and vertical.
On this side of the canyon there were great houses under the cliffs with smaller settlements across the river. Great houses were a distinctive architectural development of the Chacoan people. They are multi-roomed settlements where the rooms are interconnected rather than separated. Some have hundreds of rooms.
Una Vida had around 160 rooms, including some with two storeys, four kivas and one or two great kivas. Doorways were low and ceilings were made with wooden poles which now allow dating of the various buildings by dendrochronology - the desert preserves wood very well.
Our guide told us that Navajo were pursued into the canyon by the Spanish who, thinking that they couldn't possibly survive here, left them. However, they did survive and the rough walls at Una Vida, made from collapsed Chacoan walls, are theirs.
We climbed up behind the ruins to get closer to the cliff face where there are some very nice petroglyphs, though some are a bit difficult to make out.
We stopped only briefly at largely unexcavated Hungo Pavi as it is similar to Una Vida. It is D-shaped, a classic shape for Great Houses, and had around 140 rooms, some to three storeys, with the earliest buildings dating from the late 900s.
Chetro Ketl, on the other hand, is much larger. A classic D-shaped Great House it is the second largest in the canyon with 4-500 rooms, some blocks up to four storeys, multiple kivas of different designs and two large kivas in a wide plaza.
A very rare feature of Chetro Ketl is the long wall facing south into the plaza. It was once colonnaded, the spaces between the columns now filled in. It is known the Chacoans traded with cities in northern Mexico and it is thought that the colonnade was an idea borrowed from there.
At least two storeys here, with a stone-lined pit at one end of the lowest floor.
The central plaza was elevated 12 feet above the surrounding landscape, a very unusual feature, requiring tons of hard-packed earth and stone to construct.
Within the plaza are the two large kivas called the Court Kiva and Great Kiva. The Great Kiva is huge, 62.5 feet in diameter, one of the largest in the canyon.1
The Great Kiva has numerous internal features including a firepit, circular and rectangular floor cavities, a bench encircling the wall and an entrance from an antechamber. It is built on top of another, earlier, Great Kiva.1
The circular floor cavities may have once held roof supports. The rectangular floor vaults may have had a timber covering, possibly used as foot drums .
Leaving the Great Kiva we headed to a number of smaller kivas closer to the cliffs. There are six in all in this location with different features, two actually conjoined. Five below ground and the largest above ground and built into the Great House rooms.
We moved on to the Great House living quarters and more kivas. Our guide told us that one tower kiva proved difficult to build, continually collapsing, until buttress walls were used to support it, disguised as rooms, though no-one lived in them and nothing was stored there.
Looking at the interactive map on the Chaco Research Archive site1 there are corner spaces around the towers which could well be unused, formed simply due to a circular tower being surrounded by rectangular rooms. From the way the walls butt up against the tower it looks like the tower was built first so various room walls could be buttressing it.
Another strange feature of Chetro Ketl is a very long wall, about 480m, on the north side aligned with the "lunar standard"2. The moon rises over one end at a particular time, then 9 years and three months later it rises over the other end. This seems very strange to me. They'd have to be observing and recording the moon rise for decades to figure this out. And what is so special about these particular times?
There seems to have been some competition between Chetro Ketl and Pueblo Bonito. A spurt of building at one, to make it the biggest, was followed by a spurt at the other to retake the lead!
We walked back west along the cliff face where there are lots of petroglyphs.
Quite close to the back wall of Chetro Ketl is another small structure, called Talus Unit, composed of two sets of interconnected rooms, each with kivas.1
There are quite a lot of petroglyphs chipped and scraped into the cliff face. Lots of humanoid figures and spirals which we'd seen many of at Petroglyph National Monument and also at Mesa Verde in Colorado.
The petroglyphs are high up on the cliffs. We know that the people of this time were very nimble, using hand and toe holds carved out of the rock to climb cliffs. They also used ladders to access their buildings.
Some of the spirals are near-perfect.
After lunch at a shaded picnic table we walked on to Pueblo Bonito, the most famous and also the biggest of all the Chacoan Great Houses.
