Sun-Dagger Sites

Reference work entry


This chapter reviews characteristics of several so-called sun-dagger sites, including the archaeological, geological, and cultural contexts in which they are found. It also raises issues regarding the analysis of sun-dagger sites relating to their artistic, geological, archaeological, and astronomical contexts.


Archaeological Site Concentric Circle Summer Solstice Winter Solstice Center Slab 


The term “sun dagger” has come to refer to a set of phenomena in which sunlight and stone edges interact in such a way as to cast a sharply defined pattern of light at a calendrically significant time of year across a stone surface that generally contains a pictograph or petroglyph. Sun daggers are a special case of a broader use of the interaction of the sun and shadow to produce a “sacred showing” or heirophany (Eliade 1959; McCluskey  Chap. 28, “Analyzing Light-and-Shadow Interactions”, this volume).

The term “sun dagger” was popularized not only in the archaeoastronomical literature but also in the eye of the broader public after a sun-dagger type phenomenon was discovered on Fajada Butte in Chaco Canyon, New Mexico (Sofaer et al. 1979), and widely publicized (see  Chap. 18, “Archaeoastronomical Concepts in Popular Culture”). The term has come to refer to a broad class of related solar phenomena yet is especially descriptive of only the one particular event, in Chaco Canyon, New Mexico. Visual appearances at other sites would be more accurately described, as noted below, in quite different terms. Nevertheless, it is very difficult to find a general term applicable to all cases to replace the “sun dagger” appellation.

The following paragraphs review four selected sun dagger manifestations at archaeological sites in the southwestern and western United States and Mexico.

Holly House Sun Serpent

This petroglyph site, near several well-preserved Ancestral Pueblo stone structures in Hovenweep National Monument dating between AD 1200 and 1300, is of archaeoastronomical interest because it contains a pecked symbol of 30 cm diameter made up of three concentric circles with a dot in the center and because sunlight reaches the panel between the first of March and the last of October (Williamson and Young 1978). In Pueblo culture, similar concentric circles often represent the sun (Ellis 1975, p. 74). The petroglyphs lie on the south face of boulder in a natural east-west corridor formed by two very large boulders (Fig. 43.1). Other pecked symbols on the rock face include two pecked spirals about 30 cm across, a meter-long undulating line that may represent a serpent, a small twin-like figure, and two forms each resembling a reverse S.
Fig. 43.1

Artist’s drawing of the petroglyphs near Holly House, Hovenweep National Monument. Artist: Snowden Hodges

A solstitial connection with the petroglyph panel was confirmed in June 1979 (Williamson 1979). In that event, 6 days prior to the summer solstice and 45 min after local sunrise, a sliver of sunlight entered the narrow corridor and began to move horizontally across the left hand spiral, broadening as it moved across the second spiral. Then another sliver of light appeared to the right of the concentric circles and snaked toward them. One minute later, the two slivers of light met about halfway between the concentric circles and the rightmost spiral and expanded downward to illuminate the entire petroglyph panel. Observers commented on how much like serpents the slivers of light looked as they moved toward each other across the petroglyph panel.

Periodic observations over several years from early March through the autumnal equinox showed that the site could have been used as an accurate predictor of the arrival of summer solstice (Ambruster and Williamson 1993), and indeed of important spring planting dates, critical to this dry desert environment. That the inhabitants of the area in the thirteenth century likely observed the solstices is confirmed by several structures that manifest well-defined solstitial astronomical alignments and by historic references to similar sunwatching practices by their descendants (Williamson 1987, pp. 112–132; Cushing [1882–3] 1967, p. 41).

Fajada Butte Sun Dagger

First discovered during a rock art survey of Chaco Canyon, New Mexico, in 1978, this phenomenon appeared on a carefully pecked spiral petroglyph about an hour before noon near the summer solstice (Sofaer et al. 1979). The spiral is one of two located on a south-facing boulder behind three large vertical stones, which in 1978 allowed sunlight to penetrate to the center of the spiral, forming a well-defined shape resembling a sharp dagger of light. Sofaer and her colleagues also established that the boulders formed similar patterns between 10 and noon local time throughout the year, though the particular appearances changed in the course of a year. At the equinoxes two light daggers appear, one to the right of the center of the spiral and one bisecting a smaller spiral to the upper left of the larger one. At the winter solstice, the two light daggers nearly frame the larger spiral.

Sofaer and colleagues (1979) originally suggested that the site was the result of careful engineering by the early inhabitants of Chaco Canyon. Nevertheless, other researchers, with geological knowledge of the area (Newman et al. 1982) demonstrated that the stones most likely originated as horizontal layers in the sandstone above the site and came to rest as vertical stones over time by a slow, natural process aided by weathering and the annual freeze-thaw cycle.

La Rumorosa, Baja California

California and Baja California host several sun-dagger sites with possible solstitial connections. These sites are of particular significance because they are likely to be related to groups of hunter-gatherers, not agriculturalists, in contrast to the case of the U.S. Southwest Pueblo groups. Near the tiny town of La Rumorosa in Baja California, Mexico, a small rock shelter contains, among other images, a small red anthropomorph with wavy, hornlike appendages extending from its head (Hedges 1986). About 20 min after sunrise, a triangular band of light appears and over the next 20 min moves toward the red figure, lights up the face, then expands downward to cover the whole figure except for the horns before fading (Fig. 43.2). As part of the overall light display, another beam of light falls across a milling slick that may have been used for grinding pigments or seeds, emphasizing that important feature. Archaeological evidence in the area suggests that this site was likely created by the Kumeyaay Indians, who, though they practiced no agriculture, closely observed the sun and held ceremonies to celebrate both the winter and summer solstices.
Fig. 43.2

From Williamson RA (1987) Living the sky: the cosmos of the American Indian, p. 271 Artist: Snowden Hodges

Mutau Flat

The Chumash Indians of California, also hunter-gatherers, followed the sun’s path along the horizon throughout the year and developed elaborate rituals centered on the arrival of winter solstice (Hudson and Underhay 1978). They also created elaborate polychrome pictographs throughout their territory. Several sun dagger sites are known in the area that appear to be related to the Chumash. Their characteristics and sun dagger appearances are summarized by Krupp (1993).

Krupp also recorded a rather striking summer solstice event at Mutau Flat, in the Los Padres National Forest, which like the Holly House serpent-like appearance, involves the touching of the tips of two blades of light. The wall of one of the painted shelters in Mutau Flat contains several typical paintings, including a figure resembling a shaman in ceremonial skirt. Shortly after 09:00 PDT on the summer solstice, two small triangles of light appear on opposite sides of a natural shelf below the paintings and begin to move toward each other as they grow larger. In a few minutes, the two triangles of light elongate and meet at a “finely painted red line”, then merge into a single wide strip that moves to the north and gradually illuminates the shelter. Then at 9:45, this band of sunlight begins to illuminate a shallow stone bowl carved out of the top of a boulder attached to the floor of the shelter.

About an hour later, a shadow begins to move across the lighted dish until it is one-half covered and then slowly rotates clockwise for the next 2 h and retreats. This detail may have been important to the Chumash because for them the summer solstice divides the year in half (Krupp 1993, p. 261). A second shadow covers the stone about one-half hour later and remains for the rest of the day. Later visits to the site demonstrated “a distinct difference in the behavior of the two knives of light 8 days before or after the summer solstice”, which suggests (Krupp 1993, p. 260) that the shelter functioned as a shrine to celebrate the solstice rather than an observatory.

Interpretive Issues

Several issues plague the interpretation of sun-dagger sites. Considerations in each issue category can drastically affect our understanding of the relationship of these archaeological sites to the cultures that created them. The following paragraphs discuss these important issues.

The Archaeological Context

As is the case with all interpretations of archaeological sites, we are limited to what can be substantiated by the archaeological and cultural context of the peoples who created the site. Because pictograph and petroglyph sites generally cannot be directly dated with certainty, they must be dated by their incorporation in or proximity to datable remains, or, as in the case of several California sites, also within the context of the knowledge collected historically from living descendants of the peoples who created the sites. Nor do we always know which of the area’s cultures created the sites in question. Further, several of these sites appear to be unique in the areas in which they are found, which should raise a red flag in attempting to interpret them in their cultural context.

The Cultural/Artistic Context

All sun-dagger sites contain artistic representations of one sort or another. Although it is impossible to interpret with certainty the meaning of the rock art found at these sites, interpretations should be consistent with the culture represented by other archaeological remains in the area. Introducing cultural concepts typical of other cultural areas but not demonstrated in the site under investigation should be avoided, as they may well undercut the credibility of the interpretation. Considerations that would negatively affect interpretations should be fully explored in reports so that other researchers can evaluate the reported findings.

Rafter (1995), for example, argues that the Red Lady pictograph found at the Counsel Rocks site in California could well be linked to a Chemehuevi myth about a lone woman collected by ethnographer Carobeth Laird (1984, p. 204), noting that a band of the Chemehuevi lived in the area for time in the late 1800s and could well have placed the painting in the cave. The connection between this cave and the collected myth is circumstantial, and Rafter explains his doubts sufficiently so that the uncertainties of his site interpretation are clear to the reader.

The Geological Context

Because the creation of sun-dagger phenomena is highly dependent on the surfaces and especially the edges of various types of stone, the phenomena can be heavily affected by weathering. For example, in the case of the Holly Sun Serpent site, weathering is certainly a concern because the creation of the serpent of light depends on the upper edge of the northern boulder directly across from the petroglyphs, which is fully exposed to the elements, and the lower edge of the extension above the petroglyphs, which is subject to potential surface spalling.

Changes in the stone surface of underlying petroglyphs or pictographs are also of great concern and researchers should take great care to preserve all aspects of the site. Pictographs, especially, can be subject to exfoliation in humid climates, and changes in the local environment can promote alterations of the pigment or loss of entire parts of the image over time.

Even massive stones, such as those that make the Fajada Butte sun dagger possible, face environmental challenges. As a result, we cannot expect that the detailed manifestation of the sun dagger looks the same today as it did some ten to twelve centuries earlier. Indeed, because the center slab of the Fajada Butte sun dagger site shifted position slightly sometime between 1978 and 1990 (Sofaer and Sinclair 1990), the appearance of the sun dagger changed from a sharp, stiletto pattern to an irregular one, akin to the shape of a rutabaga. Sofaer and Sinclair (1990) suggest that this shift may have stemmed from the loss of supporting and stabilizing material at the base of the center slab. This may have occurred as a result of site investigation by a variety of researchers untrained in archaeological techniques and site preservation. Whatever the cause, such changes provide a cautionary tale of not reading too much into the detailed shape and progress of the light patterns in such cases.

The Astronomical Context

For today’s researchers, and especially for scientists, within whom knowledge of Western science is ingrained, it is very tempting to impute intentionality to alignments or conjunctions that may in fact occur purely by chance. For example, Sofaer et al. (1982) have speculated that their observed lunar alignments of the large spiral on Fajada Butte indicate that the Ancestral Pueblo of Chaco Canyon paid close attention to the horizon rise and set positions during the full lunar cycle and might have used their observations to predict eclipses. Yet, as Carlson (1987) and Williamson (this volume,  Chap. 45, “Pueblo Ethnoastronomy”) argue, there is no evidence that the historic Pueblos had an interest in following the 18.6 year cycle of the moon, let alone using it to predict eclipses.


Sun-dagger visual phenomena draw researchers and the public because they delight the eye and intrigue the professional. Because the visual phenomena are so striking, they have often not received the critical examination they deserve. As the discovery of these sites continues, it will be important to subject them to the same sort of scrutiny to which other archaeological sites are subject. The analysis of McCluskey (this volume,  Chap. 28, “Analyzing Light-and-Shadow Interactions”) and Novak et al. (1992) provide good starting points for this process.



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Copyright information

© Springer Science+Business Media New York 2015

Authors and Affiliations

  1. 1.Secure World FoundationBroomfieldUSA

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