Wisconsin's Ancient Mounds*

Thomas C. Pleger, Ph.D.
UW-Fox Valley Anthropology
Copyright © 2000

Most Wisconsin outdoor enthusiasts have at one time in their lives stumbled upon or visited an Indian mound group. As a Great Lakes archaeologist, I am periodically asked about the age and purpose of these mounds. The term mound refers to an artificial as compared to a natural earthen form. In the mid and late 1800s, scholars debated the authorship of these mounds. The Smithsonian Institution investigated the issue and even conducted a number of excavations in SW Wisconsin in order to determine the origins/cultural affiliation of the mounds. Today, we know that the mounds of Eastern North America were built by a series of prehistoric Native American cultures spanning over 2,500 years.

Virtually all of the Indian mounds in Wisconsin were constructed prior to European contact (AD 1600s). Prior to turn of the century, thousands dotted the Midwest landscape; today, over 75% have been destroyed as a result of development, looting, and/or natural erosion. Archaeologists have assigned the mounds in Wisconsin to various prehistoric cultures based upon their shapes and artifactual contents.

Conical mounds ranging from several meters to over 20 meters in diameter were first constructed in Wisconsin by Woodland tradition cultures as early as 400 BC. Conical mounds usually were constructed as receptacles for the dead and may represent family or lineage burial tombs. These mounds were built by cultures of the Early Woodland stage (500-100 BC), the Middle Woodland stage (100 BC-AD 500) and the Late Woodland stage (AD 500-AD 1300).

During the Middle Woodland stage, mound building cultures participated in long distance trade and exchange in order to obtain materials as far away as the Gulf Coast of Mexico and the Great Plains. We also know that cultures began to experiment with horticulture by growing a variety of domestic and imported Mesoamerican plants.

During the Late Woodland stage, the preceding elaborate trade system declined. Populations subsisted on a corn, beans, and squash agriculture supplemented with hunting and gathering in the southern part of the state and a hunting and gathering strategy to the north.

Late Woodland stage mound building included the construction of Effigy (animal) shaped mounds for the burial of the dead. An excellent example of an Effigy Mound Culture mound group can be viewed in our area at High Cliff State Park. Effigy mounds were constructed across the southern two-thirds of Wisconsin, eastern Iowa, Northern Illinois, and southeastern Minnesota between AD 600 and AD 1300. Archaeologists believe that the various animal shapes may have represented specific clans or lineages of Effigy Mound Culture populations.

By AD 900, a new type of mound construction was taking place in the American Bottoms and as far north as southern Wisconsin. These mounds include flattop or platform-shaped mounds. Flattop mounds were built by Middle Mississippian cultures between AD 900 and AD 1250 and served as the platforms for chiefly elite homes and religious structures. Mississippian cultures depended upon an intensive corn, beans, and squash agriculture. Their villages were the largest in Midwestern prehistory. Aztalan State Park near Lake Mills is Wisconsin's best-known Middle Mississippian site. Aztalan was occupied between AD 850 and AD 1250. At its peak, Aztalan may have had a population as large as 500 people living in the village and the surrounding area. By AD 1300, mound building was in decline in Wisconsin and by the time of the arrival of the first Europeans in the 17^th century mound construction had ceased.

Today, mounds remain in undeveloped areas including many state, county, and local parks. They are protected under state statute with the intent of preserving the past for future generations. The mounds in our area can be viewed as ancient monuments, representing the complexity and diversity of prehistoric Native American cultures spanning a time frame of 2,500 to 700 years before present.

For more information about Wisconsin archaeology, please visit the UW-Fox Valley Anthropology web site at: www.uwfox.uwc.edu/academics/depts/ant.html.

*Originally published in the Appleton Post-Crescent

Recommended Readings

Birmingham, Robert A., Carol I. Mason, and James B. Stoltman (editors)
1997 Wisconsin Archaeology. The Wisconsin Archeologist, Volume 78, Number 1/2, The Wisconsin Archeological Society, Milwaukee, Wisconsin.

Birmingham, Robert A. and Leslie E. Eisenberg
2000 Indian Mounds of Wisconsin. The University of Wisconsin Press, Madison, Wisconsin.