The Mounds and Mysteries of Ancient Ohio

Last Updated on: 16th December 2023, 11:28 pm

Long before the first European settlers arrived, the Ohio region was home to some of North America’s most advanced civilizations. As they left behind no writing, we know relatively little about them. But we do know that the Adena, Hopewell and Fort Ancient peoples, as they’re called today, loved to build mounds. And masterpieces like the Serpent Mound and Newark Earthworks, which have braved the elements for thousands of years, continue to mystify researchers and ordinary visitors alike.

Ohio’s mounds, in fact, were featured in the Smithsonian Institution’s first ever publication. Archaeologists Ephraim George Squier and Edwin Hamilton Davis extensively surveyed the mounds for years before releasing the large volume called Ancient Monuments of the Mississippi Valley in 1848.

Their book, full of accurate maps and descriptions of the various mound types, remains invaluable to researchers to this day. And throughout the following guide, you’ll find find both illustrations and relevant quotes from Squier and Davis’s influential work.

I decided to follow in Squier and Davis’s footsteps after visiting the forgotten pyramid of Cahokia in southern Illinois. Wondering what other mysterious sites there were to explore in the Midwest, I learned that Ohio is one of the region’s best states for those with an interest in lost civilizations.

The state is home to dozens of ancient sites which would probably take weeks to explore in full. The attractions featured below, however, are all located in central and southern Ohio. I was able to see everything over the course of two full days. A scheduling mishap, however, would cause me to miss out on Fort Ancient, another one of the region’s top mound sites.

The Hopewell Mound City Group

The first stop of my trip was the Hopewell Mound City Group, just outside of the city of Chillicothe. The mound was built by the Hopewell culture a few thousand years ago. And in fact, Mound City contains the largest concentration of mounds of any Hopewell Settlement, totaling 24.

The group of mounds takes up an area of 13 acres, and it was all surrounded by an elevated barrier. But the barrier was unlikely meant for defense. If so, then what was this site’s true purpose?

Mound City

Mound City was likely a sacred space used for special rituals and burials. Supposedly, each mound had its own accompanying structure. Archaeologists believe that these buildings would’ve been used for cremation ceremonies before placing the ashes within the mound. 

Ashes and bone remnants, in fact, have been found in the very center of many of the mounds, close to ground level. And when the mounds were first excavated in the 19th century, archaeologists also found various effigies, stone tools, copper artwork and obsidian spear tips. 

Notably, materials found within the mounds came from as far away as the Gulf of Mexico, the Atlantic Coast, the Rocky Mountains and Canada. That means that the Chillicothe area, now a sleepy town of 20,000, was once the heart of a vast trading network.

Hopewell Culture National Historical Park

Who Were the Hopewell?

The Hopewell culture thrived throughout the Midwestern US from around 1 – 500 AD. The term, however, is merely a broad label for various Native American tribes that shared similar cultural traits. There was unlikely a unified group that called themselves by a single name. And if they had, it certainly wouldn’t have been Hopewell!

The name, in fact, derives from Mordecai Hopewell. He was the man who owned the land on which Mound City was first discovered in the 19th century. As luck would have it, he’d get to have an entire prehistoric civilization named after him!

We know little about Hopewell culture overall. But we do know that, in addition to being skilled artisans, the Hopewell had a very sophisticated knowledge of astronomy and geometry. This is not only evidenced by sites like Mound City, but also the mind blowing Newark Earthworks complex, which you’ll learn more about down below.

Believe it or not, nearly all the mounds at Mound City today are reconstructions, as the site was deliberately destroyed during World War I. For whatever reason, this was the spot that the US military chose for a training base called Camp Sherman. 

As I walked around Mound City – the only visitor that day – I was confused as to why the place ever needed to be destroyed. While far from being the biggest state, Ohio remains a pretty vast place, with lots of open, unused space. While I’m unaware of the planning that went into establishing Camp Sherman, couldn’t they have just moved it down the road a bit? It makes one wonder if someone in charge back then wanted to deliberately destroy the mounds. And if so, why?

Mound 7

After the war’s end, at least, Camp Sherman was eventually dismantled. And archaeologists were able to recreate the mounds based on prior surveys and excavation work. But there was still one mound that was left alone during the war – Mound 7.

Mound 7 is also the largest mound of the entire group, standing at over 17 feet high. The remains of thirteen different cremated bodies were found here, along with copper objects from as far away as Lake Superior. 

Hopewell Culture National Historical Park
Elliptical Mound
A former ceremonial place

Other highlights of Mound City include the Elliptical Mound (Mound 3), which stretches out to 140ft long. Its true purpose is unclear, but it may have had a relationship with the two circular mounds nearby it.

Another interesting section of Mound City is where the post holes of an ancient structure are marked. This was likely a long, oval-shaped building. Some believe the structures were used to cremate bodies before placing them where a new mound was set to be built.

Hopewell Culture National Historical Park
Hopewell Culture National Historical Park

While we don’t know how many trees would’ve been here during the Hopewells’ time, this whole area would’ve been covered in dense forest when Squier and Davis first came across it. 

Interestingly, Mound 1 has been preserved to appear as the original surveyors would’ve found it. And it was also this particular mound that Squier and Davis used as an example in their book to show what mound looked like on the inside:

Hopewell Mound City Mound 1

This mound was an ‘Altar Mounds,’ used for rituals or possibly sacrifice (but of what kind we can’t say for sure). At the bottom is an altar of burnt clay, on top of which sits bones or ashes. This particular mound had mica sheets above the ashes, but that was rather uncommon.

A skeleton was found buried at the top, but it didn’t belong to the Hopewell. Much later, Native American tribes with no connection to the ancient mound building cultures would occasionally bury their dead within existing mounds. As you might expect, this has caused a lot of confusion for excavators over the years.

'They are the principal depositories of ancient art; they covered the bones of the distinguished dead of remote ages; and hide from the profane gaze of invading races the altars of the ancient people.'

Hopewell Culture National Historical Park
Part of the original outer boundary wall
Hopewell Culture National Historical Park

Just outside the ‘city limits,’ visitors can access a scenic nature trail along the Scioto River – likely a very significant river for the Hopewell. But as I had a lot more to see that day, I returned to Mound City and made a quick stop at the Visitor Center before moving on.

The true purpose of Mound City remains a mystery. The layout of the mounds as seen from above almost looks like some kind of secret code. Perhaps it’s a mirror of some constellations that appeared to the Hopewell in the night sky? 

Whether or not that’s the case, scholar William Romain has discovered that the diagonal axes of the ‘city’ align to both the summer solstice sunset and the trajectory of the Milky Way. And it may even have a direct connection to Newark Earthworks, an even larger Hopewell masterpiece. But more on those earthworks later.

Hopewell Culture National Historical Park

If you have more time to spend, Mound City is just one part of the Hopewell Culture National Historical Park. Other nearby sites that make up the park include the Spruce Hill Earthworks, Seip Earthworks, the Hopewell Mound Group, the Hopeton Earthworks and the High Bank Works (currently closed).

The Leo Petroglyph

My next destination was the Leo Petroglyph, the only stop on my trip to not feature a mound. The carvings were supposedly left by the Fort Ancient civilization, the successors to the Adena and Hopewell cultures who flourished around 1000 – 1650 AD. 

Among the shapes carved in the large sandstone bedrock are a bird, footprints, and a creature with horns. The horned creature, notably, has a distinct ‘smiley face.’ It even reminded me of a similar rock carving I’d come across on the opposite end of the world in Borneo.

Leo Petroglyph
Leo Petroglyph Ohio
Leo Petroglyph Ohio
Leo Petroglyph Ohio

A wooden viewing platform allows visitors to observe the various carvings from different angles. While the petroglyphs only take a few minutes to see, don’t miss the hiking trail just behind it, which takes you to a stunning bedrock gorge.

Leo Petroglyph Ohio

Serpent Mound

If you’re going to visit one ancient site in Ohio, make sure it’s Serpent Mound, located in Adams County. Not only is it one of the most mysterious archaeological sites in the entire country, but it’s also one of the most interesting to look at.

Other than those who lived in the immediate vicinity, few people knew about the site until the 1840’s, when Squier and Davis came to survey the area. In order to protect the mound, the land was first purchased by Harvard University and then the Ohio Historical Society in the year 1900.

Arriving a few hours before sunset, I headed straight for the observation tower. Seeing the site from above is a must to clearly view the serpent’s curves in all their glory.

The largest animal effigy mound in the United States, the majestic serpent would stretch out to over 1300 feet were it built in a straight line. Supposedly, the mound dates back to well over 2,000 years ago. And to this day, researchers are still scratching their heads over how such a ‘primitive’ civilization could build something so large, sophisticated and beautiful.

Serpent Mound is generally attributed to the Adena Culture, a civilization which inhabited the region from around 800 BC – 100 AD. And while we don’t know a whole lot about them, the Adenas likely left a major mark on subsequent civilizations like the Hopewell and Mississippians

Even from the observation tower, the entire effigy can’t be taken in all at once, and an illustration (or drone) is required to fully make sense of it. 

The southern end of the serpent is a tail which coils around three times. And over at the opposite end, which is hard to get a clear glimpse of from the tower, the head of the snake appears to be devouring a large oval-shaped object – possibly an egg, or maybe the sun.

But why a serpent, and what does it all mean?

First, let’s consider the location. The effigy is actually situated on a ridge within a huge crater that was formed by a meteorite around 250 million years ago. The overall crater is huge, with a total diameter of 14 kilometers. And supposedly, some people still notice magnetic anomalies in the area.

We don’t know whether or not the Adena were aware of the crater, as it’s hard to see with the naked eye. But the meteor strike did cause various caverns to form around here, which perhaps the Adena considered to be portals to the underworld.

Serpent Mound Map
Rural Adams County as seen from the coiled tail of the serpent.

The mound is also situated right by a tributary of the Ohio Brush Creek. And throughout various world cultures, including numerous Native American groups, caverns and water have long been associated with the underworld. And if there’s one animal that’s most typically associated with this lower realm, it’s the serpent.

But the Serpent Mound may have acted as more than just a symbol of the world below. It also seems to have functioned as a mirror of the world above.

Serpent Mound Ohio
Serpent Mound Ohio

I walked along the paved path which takes visitors to the head of the snake. When Squier and Davis arrived here in the 19th century, they noticed, sadly, that this area had been vandalized – possibly by someone looking for gold.

The outline of the head and oval-shaped object is difficult to make out from ground level.  But take a look at the illustration above, and notice the triangle where the serpent’s head is. By standing here and looking directly over the egg in a northwest direction (an azimuth of 300.1 degrees), one can get a perfect view of the sunset on the day of the summer solstice.

Serpent Mound Ohio
Serpent Mound Ohio
Serpent Mound Ohio
Serpent Mound Ohio
Serpent Mound Ohio

Meanwhile, the same tip of the ‘arrow’ connected with the center of the serpent’s tail, precisely marks true north. Some scholars even speculate that each curve of the serpent’s body points to certain celestial phenomenon. Signs placed around the site mark where one can see sunrises and sunsets on the solstices and equinoxes, but the curves aren’t perfect. Many of them are several degrees off.

Be that as it may, back at the tail, standing at the first curve and looking straight over the center of the triple coil, one can get a perfectly aligned view of the winter solstice sunset. Clearly, the Adena knew exactly what they were doing!

Serpent Mound Ohio
Serpent Mound Ohio

William Romain has also discovered yet another fascinating correlation. During the sunset of the summer solstice, when one stands at the point of the arrow in the snake’s head, looking directly south, one can see the constellation Scorpius rising above the horizon. 

Interestingly, Scorpius looks very much like the Serpent Mound itself! There’s still a lot we don’t know about Serpent Mound, but the aphorism ‘As above, so below’ (or the Adena language equivalent) was clearly a major inspiration for its construction.

Access to Serpent Mound is ‘technically’ free, though an $8 parking fee is charged per vehicle. And there’s certainly no way to get here via public transport.

Before leaving, I checked out the Visitor Center, which provides some interesting information on how the mounds were likely built. Furthermore, you can also find a timeline which compares the construction dates of various ancient sites throughout the world, such as Teotihuacan and Angkor Wat.

Miamisburg Mound

I spent the night at a motel in the small city of Hillsboro, which, incidentally, happens to be Edwin Davis’s hometown. And the next morning , I’d start heading back north. My first stop of the day was Miamisburg Mound.

The huge mound is 68 feet high, 852 feet in circumference, and consists of over 310,000 cubic feet of earth. Its sheer size makes the green humps of Mound City look like anthills in comparison.

Miamisburg Mound
Miamisburg Mound Ohion

The Miamisburg Mound is attributed to the Adena culture, the same civilization that likely built the Serpent Mound. That effigy mound was unique even for the Adena. Typically, Adena mounds were conical in shape, but none as big as this one. It may even be the largest conical mound in the world! And it’s been standing tall like this for over 2,000 years.

Miamisburg Mound Ohio
Miamisburg Mound Ohio

The Miamisburg Mound became locally well known as soon as the earliest United States settlers arrived in the early 1800’s. The mound was eventually gifted to the Ohio Historical Society in 1929, and the state turned it into a tourist attraction in the 1930’s. Yet, over 80 years later, it’s baffling to consider how so few people know about it.

Today, a modern staircase takes visitors to the top of the mound. I relaxed at the top for awhile, taking in the 360-degree views of rural Miamisburg. 

But what was the mound’s purpose? Excavations in the 19th century revealed two vaults within the mound’s core, one of which contained a skeleton. But as it was built by the same people who constructed the Serpent Mound, it likely played some additional roles as well. 

Miamisburg Mound Ohio

'But rude as are these primitive memorials, they have been but little impaired by time, while other more imposing structures have sunk into shapeless ruins.'

Glen Helen Nature PReserve

My next destination was the Glen Helen Nature Preserve, just nearby by Antioch College. It’s a beautiful forested area full of dense forest and scenic walking trails. And supposedly, it was also once home to hundreds of mounds. But sadly, today there are very few left.

Glen Helen Nature Preserve Ohio
Glen Helen Nature Preserve Ohio

One of the main highlights is the vertical-standing ‘Skull Rock.’ There’s no way this formation would’ve gone unnoticed by the local Hopewell population. And it may have prompted the natives to use this site as a necropolis, as researcher Fritz Zimmerman describes it.

Nearby is the impressive spring known as ‘Blood Spring,’ which locals still come to drink out of today. 

While unfortunately, many of the ancient mounds in this area have been destroyed, there’s at least one mound around here that’s even marked on Google Maps. I went to the spot and didn’t see anything, and so I decided to do some light hiking around the area. The area is gorgeous, no doubt. But I never came across anything close to resembling a mound.

Glen Helen Nature Preserve Ohio
The mound?
Glen Helen Nature Preserve Ohio

Only after giving up and making my way back to the entrance, I happened to pass by a group of school children on a field trip. And just then, their teacher was pointing out the mound in the middle of the forest. I’d passed by the spot a couple of times, but the mound was so hard to make out that I didn’t even notice it!

One wonders, then, what other secrets may still be lurking deeper within the forest.

NewarK Earthworks

After the Serpent Mound, the Newark Earthworks is arguably Ohio’s most impressive site – either ancient or modern. Yet very few Americans, let alone Ohioans, have ever even heard of it. Like the Serpent Mound, these earthworks only start to make sense when looked at from above. But even then, it’s not so clear at first what the Hopewell were hoping to accomplish.

The massive site, much of which has been destroyed, originally took up a space of over 2 square miles. Today, the main attraction is ‘Circle E’ shown at the bottom of the illustration below.

'These works are so complicated, that it is impossible to give anything like a comprehensible description of them.'

Newark Earthworks
Newark Earthworks

At the entrance to Circle E, there are walls on either side which form an entranceway. They stretch out to around 100 feet. The huge circle itself, meanwhile, takes up around 30 acres, stretching out to around 1250 feet in diameter. 

It’s a truly massive earthwork that’s difficult to get a feel for even when you’re standing inside of it. As such, it’s also incredibly difficult to capture in photographs.

The height of the raised embankment which forms the circle varies from place to place. But it’s generally as high as 10-15 feet. Interestingly, there’s a fairly deep ditch inside of the circle, but not on the outside. Clearly, whatever this was, it wasn’t built for defensive purposes. 

Newark Earthworks Ohio
Newark Earthworks Ohio

At the very center of the circle, I arrived at what seemed like a group of tiny mounds grouped together. Some archaeologists believe it resembles an eagle. But of course, no one really knows for sure. And at some point, before the small mounds were put in place, a wooden structure also once stood at the spot.

The eagle, in fact, is perfectly aligned with the moon’s minimum north rise when looking toward the entranceway. And the other circle, Circle F, is aligned to the moon’s maximum north rise. And the angle between the two circles marks the summer solstice sunset.

Newark Earthworks Ohio
Newark Earthworks Ohio

The circle is right in the center of Newark, a small town not too far from Columbus. While Newark Earthworks probably doesn’t get too many outside visitors, I saw several people walking about, presumably locals. In the very center, I spotted a man meditating atop the eagle effigy, and after some time had passed he came over to speak with me.

He was a local, and had been coming here daily over the past couple of weeks, he said. During sunsets, he mentioned seeing some unusual colors in the sky, which compelled him to visit regularly. I asked if he was aware of the earthworks’ celestial alignments. ‘Nah, I don’t read,’ he told me. He seemed to be implying choice rather than ability, but I wasn’t totally sure.

Newark Earthworks Ohio

Clearly, these ancient structures still have a magnetic pull which seems to draw all sorts of interesting people in to this day.

Moving on, I discovered the ‘Wright Earthworks,’ which is actually what remains of the square in front of Circle E on the map above. Obviously, this particular portion of Newark Earthworks has lost much of its magic.

But what about the ‘roads’ between the various circle, squares and octagons? What was their purpose? While we don’t really know, Romain thinks that the long road extending southward out the octagon is of special importance. 

It’s possible that during the night of the summer solstice sunset, this road marked the trajectory which the Milky Way took in the night sky. And to the Hopewell, the Milky Way represented the path that souls must traverse in order to successfully make it to the ‘other side.’

Newark Earthworks Wright Earthworks
The Wright Earthworks

Alligator Mound

Earlier in the day, I’d also stopped by Fort Ancient, the site after which the entire Fort Ancient culture was named. The attraction, located in Lebanon, Ohio, is home to some more mounds in addition to artifacts left behind by that civilization. But it happened to be a Monday, the one day of the week that Fort Ancient is closed.

I was, at least, able to make it to a special mound built by the Fort Ancient Indians. Aside from the Serpent Mound, in fact, this is the only other large animal effigy mound in all of Ohio. It was likely built at least 1,000 years later, however.

Alligator Mound Ohio

Just about 4 miles outside of Newark, the mound can be found on top of a 150 – 200 foot hill. Walking along it, it appears to be not much more than a series of random humps. But from the sky, it forms the distinct shape of an animal. It may be an alligator, a lizard or possibly even a mammal like a panther.

In total, it stretches out to around 250 feet long. And within the effigy, researchers found an old stone circle comprised of burnt stone.

Could this have possibly once been the spot for important rituals – maybe even sacrifices? Probably. But today, it acts as a tranquil little green space in the middle of an upscale suburban roundabout.

Alligator Mound
Alligator Mound Ohio
Alligator Mound Ohio

While most people have at least seen a photograph of Serpent Mound, the ancient history of Ohio remains largely unknown to most Americans. Yet these sites were clearly much, much more than pretty animal images made of dirt. 

The Adena, Hopewell and Fort Ancient cultures were undoubtedly highly sophisticated civilizations. And as painful as it may be for some to admit, there’s a lot we have to learn from them, even in our modern, ‘progressive’ era. 

Could there possibly be secret ‘codes’ embedded in sites like the Newark Earthworks that are still waiting to be cracked? As word on these prehistoric monuments gradually gets out, perhaps we may soon get an answer.

Additional Info

The best order in which to visit the sites all depends on where you’re staying in Ohio. Coming from the northern part of the state and returning there the next day, the order described above worked well for me. Though I suppose I could’ve started with Newark Earthworks on the first day while saving the Serpent Mound for the next morning.

As mentioned above, I went all the way to Fort Ancient but found it closed. Had I gone, I might not have had time to see all the other sites before sundown. If you’re on a similar schedule but want to visit Fort Ancient, I’d recommend skipping the Glen Helen Nature Preserve to save some time.

Getting around to all the sites mentioned above requires you to have your own vehicle. It may be possible to stay in towns like Colombus and Dayton and to take a taxi to get to some of the nearby mound sites. But this would be both an expensive journey and it’d require a whole lot of extra time.

All the sites mentioned above can be seen over the course of two days. In my case, this time frame also included the drive back and forth from the northern part of the state. If you’re interested in traveling Ohio specifically to see the mounds then Columbus or Cincinnati would make the best bases.

As mentioned, I stayed at a motel in Hillsboro, Ohio, situated right in between the Serpent Mound and Fort Ancient. Again, if you’re in Ohio just for the mounds, this wouldn’t be a bad base from which to see all the other sites over the course of a couple days.

Ancient Monuments of the Mississippi Valley by George Squier and Edwin Hamilton Davis can be read in full for free right here.

Also, be sure to read this fascinating presentation by William Romain, who goes into deep detail about the cosmological significance of the mounds and the possible connections between them.

The famous mounds of Ohio (together with Cahokia) are featured prominently throughout Graham Hancock’s recent book America Before: The Key to Earth’s Lost Civilization. My visit to the mounds took place before the release of the book. And while I haven’t read the whole thing yet, I’ve had a look at some of the chapters pertaining to the places I went to.

If you’re unfamiliar with Graham Hancock, he’s a major proponent of the idea that a unified, advanced civilization once flourished throughout the planet. Hancock attributes many ancient and sacred sites around the world to this mysterious lost culture, or at least their descendants. Supposedly, a major calamity wiped them out around 11,000 years ago.

Hancock brings up a lot of fascinating points. But in my opinion, just because distant cultures around the world make use of similar archetypes, such as serpents and birds, does not necessarily mean they’re descended from the same people. If anything, it says more about how the human psyche is wired. I don’t really think that the Serpent Mound is 11,000 years old, as Hancock hints at. But who knows, maybe it could be!

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