The ancients achieved amazing feats of engineering with the most basic tools and techniques, leaving structures that their descendants would puzzle over for centuries to come. Many such structures come readily to mind—Stonehenge, the Great Pyramids of Giza, and the Nazca Lines are just three of the most famous.
However, the building of such structures is not often associated with the Native Americans of North America, with the exception of the massive pyramids built by the Aztecs and Mayans in Central America. Contrary to popular belief, the indigenous tribes of what is now the United States did engage in massive projects that could rival even those of the Old World. One of these massive structures is located in Adams County, Ohio. Dubbed the Serpent Mound, the huge effigy remains an enigma to this day.
The Serpent Mound is one of hundreds of mounds built by Native American tribes in Ohio. Most mounds are conical structures used to bury and memorialize the dead, while some of the more massive mounds are effigy mounds, meant to be representations in earth of various animals. The Serpent Mound is among the largest and best preserved of these effigy mounds. Measuring 1330 feet in length and 3 feet in height, the mound is a depiction of an undulating snake with a curled tail, possibly with its jaws open to swallow an egg. There is some dispute as to what the effigy is meant to depict, with some claiming it is not a serpent at all but rather a stylized depiction of a comet streaking through the sky. This is indeed an interesting interpretation, since there is a meteor crater nearby, but no one knows for sure.
“No one knows for sure,” is a phrase that seems to hover over the Serpent Mound, an effigy shrouded in mystery. Even its age is in dispute. When archaeologist Frederic Putnam studied the mound in the late 19th century, he found nothing in the mound itself that revealed who made it or why. However, conical mounds situated nearby contained artifacts belonging to the Adena culture, who lived in the area from 800 BCE to 100CE. So, Putnam concluded that the site was the work of the Adena. However, evidence uncovered in 1991 disputed this age when radiocarbon dating performed on charcoal found within the mound found it to be only 900 years old. This evidence suggested that the presence of the Adena mounds nearby was happenstance, and the earthwork really was the work of the so-called Fort Ancient culture, who lived in the area from 1000CE to 1500CE. But this finding was itself overturned when a study performed in 2014 found new radio carbon dates suggesting the effigy was constructed around 300 CE, putting it firmly within the time period of the Adena culture.
So which age is right? It is difficult to tell, and more work is needed to pin point the age of the Serpent Mound as closely as possible. However, the difference in the two dates could stem from maintenance performed by later tribes who continued to utilize the site after the Adena passed into history. So, it is possible that the Fort Ancient peoples rebuilt sections of the mound, leaving behind charcoal remnants that were found by the 1991 study.
If this is the case, it might explain the age of the effigy but it leaves many other questions. Why did the Adena build the mound in the first place, and what is it meant to represent? Clearly the mound served a ceremonial purpose rather than that of a burial place. Curves in the structure show different alignments with the sun, such as with the summer and winter solstices. Could the mound be a sort of gigantic calendar, meant to help Adena and later priests track the motions of the sky? And if it was ceremonial, what sorts of ceremonies were conducted there? These questions might never be answered, as the builders left no written language explaining their thinking. All that remains is the earthwork they left behind, a silent enigma among the green hills of southern Ohio.
Author’s Note: The photographs included in this post were taken by me when I visited the Serpent Mound in 2010. I wanted to include a bit about my own feelings and thoughts from visiting the site. Some report visiting this particular mound as a spiritual experience–in fact, I accidentally interrupted a very nice woman who was meditating on the site, who said it gave off good “energy.” I had no such feelings myself, but I did find myself in awe when I was standing up on the observation tower, visualizing the Adena using little more rudimentary tools to transport the dirt and build the mound. Keep in mind, they didn’t have the wheel nor beasts of burden. Everything they built was with sheer manpower. This must have been an extremely important site to warrant such an output of blood and sweat. The Serpent Mound had the feel of the sacred, and it is a unique experience I am glad to have had.