Tremper Mound and Earthworks

Of the many peoples inhabiting the Great Eastern Forest in what is now the United States, the Hopewell Culture, spanning 50 BCE to 400 CE was one of the most artistic and geographically influential. The Hopewell peoples were not the only American Indians to build earthworks, but they certainly were the most consummate. Their works span everything from solitary mounds and earthwork enclosures to immense sacred landscapes with multiple and connecting features, sometimes aligned to cosmic celestial events.

Tremper Mound was constructed on the west terrace of the Scioto River, five miles north of its confluence with the Ohio. Built late in the first century BCE, which was quite early in the Hopewell Cultural era, Tremper Mound’s irregularly shaped 8-foot-tall mound was built on the burnt ruins of a large multi-chambered ceremonial building, enclosed by an oval earthen wall that was 500 feet across. Tremper Mound did not stand alone; it was part of a group of mounds and earthworks that were part of an even larger complex centered at the Mouth of the Scioto River. Known as the Portsmouth Earthworks, the complex spanned both sides of the Ohio River in three main centers of development.

Two separate ceremonial grounds and structures stood on the river’s south bank on the Kentucky side, roughly six miles apart. A third complex stood on the north bank of the river on the Ohio side (the site of modern-day Portsmouth), showcasing, among other features, two large and striking horseshoe mounds. Three walkways, each dramatically bordered with earthen walls, originated out of the Ohio complex. Today, nearly all of the Portsmouth Works on the Ohio side of the river lie buried beneath the city’s residential and business districts. On the Kentucky side, most of the earthworks were similarly destroyed by farming and the construction of residential subdivisions.

The nearly complete disappearance of Portsmouth Earthworks makes the preservation of Tremper Mound even more important, since Tremper is one of the few visible reminders of the splendid architecture and monumental art achieved by the Hopewell Culture in the Lower Scioto Valley.

The first surveys of Tremper Mound’s unusual shape led archeologists, including E.G. Squier and Dr. Edwin Davis, to speculate that it was designed as an “animal effigy.” Charles Whittlesey’s survey, which appeared in Ancient Monuments of the Mississippi Valley (1848), labeled it as such. It was seen as a compliment to the Serpent Mound in neighboring Adams County, but an excavation led by William C. Mills in 1915 revealed that the mound’s conformation mirrors the shape of a multi-room structure buried beneath it. What had long been speculated as an animal shape was the result of the footprint of what has been termed a “Great House,” with wood posts that had been burned before being covered by the mound construction.

In Mills’ description of the Tremper Mound Great House, he noted that the site “had been occupied by a structure serving as a sacred place, in which the dead were cremated, their ashes deposited in prepared receptacles, and the doubtless intricate ceremonials accompanying these proceedings, including the depositing of implements and ornaments of the deceased, were carried out. The structure proper had been a large oval enclosure, approximately two hundred feet long and half as wide. A number of chapel-like additions, possibly to afford more space or to supplement that of the main structure, had been built from time to time. Upright posts averaging six inches in diameter, set into the ground to a depth of about two and one-half feet, formed the outer walls of the complex structure, as well as the partitions separating them into various compartments.”

When the Great House was actively used by the Hopewell, it was divided into chambers, each alcove’s outer boundaries defined by vertical wooden poles. Walls were likely filled in with natural fibers to provide privacy and to create defined space. Some of the chambers were dedicated to mortuary purposes, with the deceased being cremated, others had specially constructed basins that communally held the ashes of hundreds of community members. There was even a chamber that seemed to have primarily served as a kitchen, presumably to feed the attendees and workers. The Great House included fire pits, possibly for ceremonial fires, and a large communal cache of over 500 articles, surmised to have been left behind in honor of the dead. Many if not most of these articles had been ceremonially broken.

As was the practice of the Hopewell, the Great House was eventually burned to the ground and then heaped over with layers of earth to form Tremper Mound as we know it today. Later yet in time, as many as sixteen burials took place on Tremper Mound by digging graves into its surface, creating what are known as “intrusive burials.” These were the only non-cremated burials ever found at Tremper Mound and they represent a later indigenous era.

Mills’s Tremper Mound excavation produced large numbers of beads, gorgets (drilled stone ornaments), copper and bone adornments; mica and galenite crystals, plugs of stone for ear ornaments; hollowed out stone “boats” that were probably rattles, a 6-inch mica bear cutout, myriad pieces of unshaped mica, and remnants of woven fabrics. Perhaps the most remarkable of all the artifacts recovered were 136 stone smoking pipes, most of them broken. Of those able to be restored, 46 were plain pipes, many of them with tall bowls. These are considered by many to be the most beautiful of the plain Hopewell pipes. Remarkably, 60 of the restored pipes were animal effigy platform pipes, a discovery that sent ripples of excitement throughout the archaeological community.

Nearly all of the artifacts removed during the Mills Excavation ended up in Columbus, in the archives of the Ohio Archaeological and Historical Society, which currently is not authorizing the public display of mortuary items from their Tremper Collection. Thankfully, a small number of items from Tremper Mound ended up in the local Collection of Charles V. Wertz, including a perfectly preserved dark pink, monitor-style platform pipe, which was gifted to him by Dr. William D. Tremper, who owned the mound site at the time of the Mills Excavation in 1915. This pipe and other Tremper Mound artifacts from the Wertz Collection are on display at the Southern Ohio Museum and can be viewed in the Scioto Historical image gallery.

Prior to the discovery of the Tremper Mound pipes, only one other cache of Hopewell effigy pipes had ever been found. It was discovered in 1846 by Squier and Davis when they were excavating Mound #8 of the Mound City Group, just forty-six miles to the north of Tremper Mound near present day Chillicothe. It was later determined that Tremper Mound was the older of the two caches, and of particular interest to archeologists was the fact that some of the Tremper pipes and the Mound City pipes were nearly identical in design.

The animals selected by the carvers of the Hopewell platform pipes were not just big game animals, nor were they only animals that were feared and admired for their power. These subjects included animals both great and small, mighty and modest - an entire rainbow of species representing the wildlife of the Hopewell culture’s home biome. The effigy platform pipes of Mound City and Tremper provide us with a field guide to the past - giving us a tour of the natural world as it existed 2000 years ago in the same environs we live in today.

Species represented on the effigy pipes included: Black Bear, Cougar, Bobcat, Porcupine, Opossum, Beaver, White-tailed Deer, Mink, Rabbit, Squirrel, Snapping Turtle, Box Turtle, American and Spadefoot Toad, Great Horned Owl, Barred Owl, Long-eared Owl, Screech Owl, Great Blue Heron, Sandhill Crane, Canada Goose, Carolina Parakeet, Bald Eagle, Bufflehead, Otter, Raccoon, Gray Wolf, Gray Fox, Domesticated Dog, and Cardinal.

Recent analysis of the stones composing the Tremper Mound pipes revealed that less than 20 percent of those tested were made from local Ohio stone, while 65 percent hailed from a northern Illinois quarry and 18 percent were made of a stone called catlinite from a Minnesota quarry, even though the Feurt Hill Pipestone Quarry was only a few miles away from Tremper. More puzzling yet is the fact that, unlike Tremper, the Mound City pipes were mostly carved out of native Ohio stone, including what is believed to be pipestone from the Feurt Hill Quarry.

Like many of their cultural counterparts, both modern and ancient, the Hopewell peoples embraced a world that was large, marvelous and varied; and they knew how to network and move resources around. They coveted “cool stuff” from far away with which to make their art: horns from Rocky Mountain sheep, shells from the Gulf Coast, copper from Michigan, and mica from the southern Appalachians. They imported silver, galena, turquoise, pearls, aragonite, meteoric materials and iron. Valuing what is rare and exotic is a universal human trait that was certainly well-expressed in the Hopewell era.

Viewing what remains of Tremper Mound and imagining the site’s Great House filled with people mourning and honoring their dead connects us across the millennia. And yet, it is important to remember that what we know about the Hopewell Culture is but a thin slice of the complexity of their artistry, traditions, and life skills. It is the Arc of Appalachia’s hope that protecting Tremper Mound will serve in a small way to expand our knowledge and appreciation of the past. The acquisition of the Tremper Mound property by the Arc of Appalachia and its transformation into a public preserve marks an important turning point in the history and preservation of the site and the larger Portsmouth Earthworks Complex.

In the words of Jarrod Burks, who has spent his career studying the archeology of the Scioto Valley, “Preserving the Tremper site is a rare opportunity to protect one of the most unique and carefully excavated mounds in Ohio. While we know a lot about what was found beneath the mound, the discovery of more details about this important early Hopewell site awaits further research in the grounds around the mound and relatively intact embankment that surrounds it. But this is only possible on the site if it is preserved. One could write many volumes about Hopewell ceremonialism simply based on what was excavated in 1915. Tremper is one of the earlier full expressions of this unique way of life that we refer to as Hopewell—especially the ceremonial side of it. It’s not only a sacred place worth preserving in its own right. It could also hold the key to understanding the origins of the Hopewell Culture in the Scioto valley.”

Tremper Mound is currently not open to the public. The Arc of Appalachia plans to open the preserve in 2023.


Jarrod Burks, "World Signifance of Tremper Mound Earthworks," Arc of Appalachia (2021).

Thomas E. Emerson, et. al., "The Allure of the Exotic: Reexamining the Use of Local and Distant Pipestone Quarries in Ohio Hopewell Pipe Caches," American Antiquity Volume 78:1 (January 2013), pp. 48-67.

William C. Mills, Exploration of the Tremper Mound (Columbus, Ohio: F. J. Heer printing company, 1916).


The Portsmouth Earthworks Complex, a 3D Simulation by Herb Roe
A 3D Simulation of the Portsmouth Earthworks Complex. The video provides a bird’s eye view of the earthworks and mounds as they may have appeared in the Middle Woodlands Period (c.200BCE to 500CE), when the Adena and later the Hopewell peoples...
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Tremper Mound is currently not open to the public. The Arc of Appalachia plans to open the preserve in 2023.