For people all over the world, an accurate understanding of the seasons and an ability to predict them was and is essential to survival. With the advent of farming, knowledge of the seasons became even more important. Planting at the wrong time could result in crop failure and starvation. Throughout the world, archaeologists have uncovered astronomical features which ancient farmers used in tracking the sun, the moon, and the stars.
While archaeological features used as solar calendars are common in farming sites, knowledge of the seasons was also a critical concern for hunting and gathering people. Hunting and gathering people, for example, did not randomly wander from one area to another. Rather, they went to areas where they knew there would be food resources that they could utilize. But if they arrived in an area too early or too late, these resources—plants, fish, animals—might not be available there and this would mean starvation.
Many different peoples, both farming people and food foraging people, have celebrated, and continue to celebrate, the changing seasons with religious ceremonies. Very often the archaeological features used as solar and/or lunar calendars were also used ceremonially. In his chapter on religion in The Oxford Companion to Archaeology, Chris Scarre writes:
“In a world without electric lights, and in regions where cloudless skies are common, the night sky would have made a powerful impression on the people’s understanding of their place in the cosmos. This is borne out by the evidence which shows that astronomical observations played a crucial part in the religious beliefs of many early societies. It has long been established that many important ritual or religious monuments were carefully aligned on solar, lunar, or stellar events, often to an astonishingly high degree of accuracy.”
Briefly described below are some of the astronomical features which have been found in ancient North American sites.
Woodhenge
One of the best-known astronomical features built by the ancient farming peoples in North America has been found at the site of Cahokia in Illinois. Founded about 600 CE, Cahokia became the largest prehistoric city north of Mexico.The astronomical feature—commonly called Woodhenge—was started about 800 CE.
Woodhenge was a solar calendar which used a series of wooden posts placed in the ground at certain intervals. Archaeologist David Hurst Thomas, in his book Exploring Ancient Native America: An Archaeological Guide, reports:
“Without question, these Mississippian astronomers followed a calendrical template.”
The calendar showed the first days of summer and winter, the first days of spring and fall, as well as other special festival dates related to the agricultural cycle.
Kolomoki
Agricultural people in Georgia established the village of Kolomoki about 350 CE. The village eventually contained nine mounds, the largest of which (designated as Mound A) was some 17 meters (56 feet) in height.
The site was laid out on a central east-west axis, with mounds at either end and a central plaza and adjoining ritual area at the center. This axis was bisected by a large, ring-shaped discontinuous earthen enclosure.
The orientation of the mounds at Kolomoki was such that they marked celestial events, including the spring equinox and the summer solstice.
McKeithen Site
In Florida, Indian people at the McKeithen site began construction of two residential mounds about 350 CE. The mounds were planned to allow the rising sun at the summer solstice to be observed and calculated from Mound B.
Ancestral Puebloan
When the Spanish first entered what would become New Mexico, they found the Native people living in large villages with multi-story structures. They called these people Pueblos, Spanish for towns. The Ancestral Puebloan culture (also called Anasazi) seems to have had its hearth in Chaco Canyon, New Mexico with outlying Chacoan towns in Utah (such as Hovenweep), Colorado (such as Mesa Verde), and New Mexico (such as Salmon and Aztec).
Sky-watching was important to the people of Chaco Canyon because an understanding of the seasons of the year enabled them to plant at the right time. There were a number of sun-watching sites which allowed people to determine the coming of the winter solstice. In his entry on astronomy in the Americas in The Oxford Companion to Archaeology, Anthony Aveni writes:
“A special petroglyph at Fajada Butte (ca. A.D. 1000) may have been used to set the approximate limits of the year via the image of the sun moving over it in the shape of a dagger of light. Other solar light and shadow phenomena indicating an interest in charting out the sun’s annual course have been reported in the architecture at Hovenweep and other Pueblo sites.”
At least one of the corner windows at Pueblo Bonito was also used to determine the arrival of the solstice.
Regarding the astronomical layout of Chaco Canyon great houses, Craig Childs, in his book House of Rain: Tracking a Vanished Civilization Across the American Southwest, writes:
“Some are oriented toward the 18.6-year lunar standstill cycle, others toward the spring and fall equinoxes.”
In Utah about 1277 CE, a solstice room was added to a D-shaped tower. Astronomer Ray Williamson, in his book The Living Sky: The Cosmos of the American Indian, reports:
“The solstice room is of generally poorer construction, and the western wall that joins the D tower is not interlocked with the D tower walls.”
All four major solar events—summer and winter solstices and spring and fall equinoxes—are commemorated in this room.
Hohokam
The Hohokam were irrigation farmers in the desert area of Arizona. They cultivated maize (corn), beans, squash, agave, and cotton. Like other agricultural people, the Hohokam used astronomy to be able to tell the coming of the seasons and thus to plant at the right times. The Hohokam flourished from about 500 BCE until about 1500 CE. In his chapter on the Hohokam in Dynamics of Southwest Prehistory, Paul Fish describes Hohokam this way:
“The Hohokam are the prehistoric farmers in central and southern Arizona below the Mogollon Rim, from the Dragoon Mountains on the east to the Growler Mountains on the west.”
Hohokam material culture shows evidence of influence from Mesoamerican cultures.
About 1300 CE, the Hohokam constructed a four-story adobe house on top of a six-foot-high earthen platform at Casa Grande. One of the intriguing features of the house is that it is built to have a calendrical function: there are wall slots which focus the sun on the opposing wall to show significant seasonal events. In his book Ancient Ruins of the Southwest: An Archaeological Guide, David Noble reports:
“One on the single-room top floor aligns with the summer solstice sunset.”
This allows for an accurate timing of certain ceremonies. Some of the openings in the building were used to record lunar cycles.
Fort Ancient
In Ohio, Indiana, Kentucky, and West Virginia, an ancient farming people called the Fort Ancient tradition by archaeologists flourished from about 1000 CE to 1700 CE. They raised corn, beans, and squash, and supplemented their diet with hunting and gathering. Their villages were planned with the houses arranged in a circle around an open public plaza.
The Sun Watch site in Ohio has been extensively excavated by archaeologists. In his chapter on Fort Ancient in The Oxford Handbook of North American Archaeology, Bernard Means reports:
“Located in the center of the village plaza are traces of a red cedar pole, which likely functioned as the site’s axis mundi, apparently used to create alignments to astronomical phenomena.”
This type of feature is also common at many Mississippian sites, such as Cahokia, and some archaeologists feel that it may indicate Mississippian influence. However, many archaeologists feel that this type of astronomical feature probably developed in situ.
Bernard Means reports:
“By incorporating celestial alignments into their overall village plan, the inhabitants of Sun Watch and other village could have reactivated on select occasions to link to the cosmos through the layouts of their villages, which represented microcosms or reflections of larger ‘realities.’”
At the Incinerator Site, the Fort Ancient people constructed a solar calendar. Five large poles were set in the plaza so that their shadows indicated the different times of the year. In his book In his book Guide to Ancient Native American Sites, Michael Durham explains:
“The complex of five poles in the plaza appears to have been arranged so that the shadow from the tall center pole lines up with the hearth of the Big House at sunrise in late April, at planting time, and mid-August, when corn is harvested.”
Shadows from the poles also indicate the solstices.
Florida
In Florida, Indian people along the Crystal River began construction of a series of shell mounds in 30 BCE. The mounds have astronomical alignments. The mounds and stone pillars were used to observe the solstices and equinoxes.
Northern Plains Medicine Wheels
Throughout the Northern Plains of Alberta, Saskatchewan, Montana, the Dakotas, and Wyoming there are 135 archaeological features commonly called Medicine Wheels. While the best-known of these features—the Bighorn Medicine Wheel—is found in Wyoming, they are most frequently found in Alberta and Montana. The Indian nations in this region generally followed a hunting and gathering lifestyle which focused on bison (buffalo) hunting.
The designation “medicine wheel” is a European descriptive term: to European eyes a circle of stones with spokes looks like a wheel. American Indians prior to the European invasion did not use wheels and would not have described these features as wheels. It would probably be more accurate to call them medicine circles or spiritual circles.
In his Ph.D. dissertation at Simon Fraser University, David Vogt describes these features this way:
“Medicine wheels are patterns of boulders found atop high hills and river plateaus over the Great Plains of North America. The usual form is a combination of features, including cairns (piles of boulders), rings (circles of boulders), and spokes (lines of boulders), all arranged in an ostensibly radial configuration.”
About six medicine wheels seem to be purposefully oriented to enable observation of rising and setting of the Sun, Moon, planets and stars for calendric or ceremonial purposes. Marking specific astronomical events, such as the solstice, is important in many Indian cultures. In some of the medicine wheels, the spokes seem to point within two degrees of the summer solstice sunrise. In his book Native North America, Larry Zimmerman writes:
“A widely-held theory is that the ‘spokes’ of a medicine wheel are (or were originally) aligned with astronomical events, such as the position of the sun at dawn on Midsummer’s Day.”
Understanding the seasons was of vital importance to Plains Indians. Kelly McDonald, in her University of Montana M.A. thesis on the Big Horn Medicine Wheel, writes:
“Markings of the summer solstice are much more common among sedentary tribes who are more likely to grow crops and therefore need a good understanding of the seasons and the solar calendar. However, medicine wheels give us evidence that the solstice was also an important event for people living on the Plains, perhaps in relation to world renewal ceremonies occurring during the summer.”
In his book Guide to Ancient Native American Sites, Michael Durham writes:
“Theories about the purpose of the wheel abound, although it is generally conceded that there is a definite astronomical aspect to it, with the twenty-eight spokes somehow relating to the length in days of the lunar month, which the Indians used to mark the passage of time.”
As noted by Michael Durham and many others, the Big Horn Medicine Wheel has 28 spokes—the number of days in a lunar month and thus it has a calendric function. However, other people have suggested that this represents the coming together of 28 different tribes.
Writing about the Bighorn Medicine Wheel in their book Native American Almanac: More than 50,000 Years of the Cultures and Histories of Indigenous Peoples, Yvonne Wakim Dennis, Arlene Hirshfelder, and Shannon Rothenberger Flynn write:
“During summer solstice, two of the cairns are aligned with the position of the sun during sunrise, and two others echo the sunset points on the horizon. Other paired piles project the directions of rising stars. Because star patterns have changed slowly over time, astronomers have determined that the closest matches between the cairns and celestial orientation points would have occurred between 1200 and 1700 CE.”
Regarding medicine wheels, Malcolm Lewis, in his chapter in North American Exploration. Volume 1: A New World Disclosed, writes:
“… it now seems probable that they were solar observatories, used in particular for solstice marking in connection with ceremonies held as much as two thousand years ago. Observing, recording, and behaving according to the stars continued to be characteristic of some Plains Indians until contact times.”
It should be noted that a number of archaeologists are skeptical of the claims regarding the use of Medicine Wheels as having astronomical orientations to solstices and bright stars.
Ancient America
The history of the Americas does not begin with European exploration. Ancient America is a series exploring Native American cultures during the thousands of years prior to the European invasion. More from this series:
Ancient America: The Marmes Rockshelter
Ancient America: The Pleistocene Extinctions
Ancient America: A very short overview of the prehistory of the Grand Canyon
Ancient America: A very short overview of Clovis
Ancient America: Kennewick Man (The Ancient One)
Ancient America: American Indians at Rancho La Brea