
Cliff Palace and Sun Temple, Mesa Verde
In addition to reports of potential astronomical features at prehistoric sites and speculations on the role of astronomy in ancient societies, Astronomy and Ceremony in the Prehistoric Southwest: Revisited contains some chapters giving guidance on methodology for archaeoastronomical research, particularly aimed at developing increased rigor that can make the results of this research more useful for archaeologists. One of these chapters, by Gregory Munson, focuses on archaeoastronomy at Mesa Verde National Park and how it can be supported or challenged by using a methodology he calls architectural documentation or “ArcDoc.”
Munson spends much of the paper laying out the details of how to do ArcDoc, which basically amounts to a standardized set of recording procedures for sites and a commitment to fully research historical archives for materials relating to site excavation and restoration. The formal procedures are apparently those used by park management at Mesa Verde, but the basic ideas here are standard pretty much anywhere archaeologists have put in place a rigorous site documentation program (e.g., on most public lands in the US).
Munson then turns to specific examples of how ArcDoc has helped clarify findings from archaeoastronomy, focusing on three sites at Mesa Verde: Cliff Palace, Balcony House, and Sun Temple. In each case, archival research has either significantly challenged findings from initial archaeoastronomical research or otherwise improved understanding of the sites.

Cliff Palace, Mesa Verde
With Cliff Palace, Munson focuses on two features in the well-known “Tower” part of the site, both of which have been proposed to have associations with lunar standstill observations. One is a vent in the wall of the tower that has been demonstrated to align with moonset over Sun Temple during the southern major lunar maximum. The other is a nearby pictograph of four vertical lines with horizontal “ticks” that has been proposed to be a record of four 18.6-year lunar standstill cycles.
The vent alignment turns out to be very questionable after looking back at records of excavation and reconstruction of the site beginning with the work of Gustav Nordenskiƶld in the 1890s and Jesse Walter Fewkes in the 1900s. Photographs from before the partial reconstruction of the site by Fewkes in 1909 show that this whole portion of the tower had largely collapsed, and the original size and shape of the vent in question is impossible to determine. Furthermore, the current vent that has the documented alignment isn’t even the result of Fewkes’s reconstruction, but of a later one by Earl Morris and Al Lancaster in the 1930s that replaced it. Munson claims that there is another opening in the wall that is more original and seems to display the same alignment, but this is an important cautionary tale for archaeoastronomers who, like many visitors, all too often assume that what they see at a site today is exactly what was there when it was originally occupied.
A similar problem affects the pictograph. The current version turns out to be a partial reconstruction by Lancaster in 1934 after two of the vertical lines had severely deteriorated, and the number of ticks on these lines does not match what appears to have been the original pictograph based on a photo taken in 1902, which Lancaster appears to not have had access to when doing his reconstruction. The numbers are still fairly close and Munson argues they could still be a record of lunar standstill cycles given the level of precision that might be expected for these observations, but still, another cautionary tale. Especially at a well-known, heavily visited, and actively managed site like Cliff Palace, you can’t assume that everything you’re seeing is original. (I used to make this point frequently to visitors at Chaco, and toward the beginning of my tours of Pueblo Bonito I would explain which parts of the masonry are and are not original.)
At Balcony House, Munson explains that proposed summer solstice and equinox alignments are thrown into question, in one case because an editing error resulted in results from observations at a different site being attributed to this one in publication, and in another case because archival research showed that a wall opening with a purported alignment had been partially sealed before impacts from recent visitation. These issues aren’t as major as those with Cliff Palace mentioned above, but they are noteworthy because they affect Munson’s own previous research, and he deserves a lot of credit for being straightforward and transparent about them.

Sun Temple, Mesa Verde
Finally, a happier story from Sun Temple. Fewkes excavated here in 1915, and a 1916 publication of his illustrates two prayer sticks found in these excavations. However, the collections from this work, housed at the park, do not include any prayer sticks. Where did they go?
Through some archival sleuthing in Fewkes’s papers at the Smithsonian’s National Anthropological Archives, it turned out that he had also excavated at Oak Tree House in 1915, and the collections from this work are now held at the Smithsonian. And sure enough, this collection turned up two prayer sticks that could be matched to those in the illustration through their shapes and distinctive cracks. The fact that these actually appear to have come from Sun Temple rather than Oak Tree House helps to better understand the history and use of both sites.
In all these cases, the understanding of potential astronomical or ritual use of specific sites has been improved by carefully examining the archival history of their excavation and reconstruction. Archaeologists are increasingly aware of the importance of looking at this history when trying to understand sites like this, but this awareness is only beginning among archaeoastronomers, and Munson’s contribution here is a welcome illustration of its value.

Vent at Sun Temple, Mesa Verde