Discover Remnants of an Ancient Culture in Iowa
Rising just 8 feet tall and 100 feet across, even the largest of the seven hills at the Toolesboro Mounds National Historic Landmark in southeastern Iowa are easy to miss. They’re not as dramatic as the Egyptian pyramids at Giza, but they were built for the same purpose: to honor the dead.
Archaeologists believe that members of Iowa’s early Hopewell culture, a Middle Woodland people, built these burial mounds between 100 B.C.E. and 200 A.D. as a way to pay tribute to prominent leaders — probably chiefs and priests — and send them into the afterlife with prized possessions from far-flung trading partners. These included objects made from glassy black obsidian from the Rocky Mountains, copper from the Great Lakes, pearls from the Gulf of Mexico and even shark teeth from the Chesapeake Bay.
Similar burial mounds and geometric earthworks have been discovered throughout the eastern half of the United States, roughly centered in Ohio. In fact, the Hopewell culture’s name comes from the 1891 excavation of a mound on an Ohio farm owned by Mordecai Hopewell. (It’s unclear what the Hopewell people called themselves since no written clues remain.)
Most mounds were built atop a floor layer of sand or clay, or a central platform upon which the bodies and artifacts were placed — either lying down or propped up in a sitting position against the sides of the tomb. Then came layers of earth, clay, sand, and gravel, piled into a conical mound.
The Hopewell people lived in villages along river flood plains and built their burial mounds nearby, typically on high bluffs. Larger clusters of mounds, such as the one at Toolesboro, probably served as ceremonial centers for regions.
The mound-building tradition in the Midwest ended around 500 A.D., either because the Hopewell groups moved south and merged with another mound-building culture known as the Mississippian, or because they blended with other tribes that honored their dead in other ways.
The Toolesboro site consists of seven burial mounds on a bluff overlooking the Iowa River near its confluence with the Mississippi River. At one time, there may have been as many as a dozen mounds, but property development and excavation have reduced that number to the present seven. So far, no village site near the Toolesboro mounds has been located, probably because the shifting Iowa River has erased most clues from the flood plain over the last 2,000 years.
The family of George H. Mosier donated the land containing the Toolesboro Mounds to the state in 1963, and three years later the site was designated as a National Historic Landmark.
No further excavations are being planned for two main reasons. First, it’s important to remember that the mounds are sacred burial sites, like modern-day cemeteries. Many people today would find it offensive if their relatives’ graves were excavated in order to learn more about how their relatives lived. While it’s difficult to trace the modern descendants of the Hopewell, further excavations of the burial mounds are nonetheless considered disrespectful.
Second, archaeology can be destructive. Opening the mounds would destroy the possibility of future study. Artifacts that are removed from a site can never be replaced in the exact position in which they were originally deposited. Currently, archaeologists prefer to use non-intrusive methods to explore ancient sites such as the Toolesboro Mounds. Non-intrusive methods include aerial photography, surface surveys, and remote ground sensory imaging, which works like a giant X-ray.
