Prehistoric Geometrical-Based Art Work on the Ground: Wisconsin’s Effigy Mounds

Prehistoric Geometrical-Based Art Work on the Ground: Wisconsin’s Effigy Mounds


This brochure illustrates a few of the many precise maps produced of Indian Mounds in Wisconsin over the past decades by students and volunteers of the Ancient Earthworks Society, working under the direction of Professor James P. Scherz, Department of Civil and Environmental Engineering, University of Wisconsin-Madison.

The first part of this document addresses some of the basic facts concerning the unique effigy mounds of Wisconsin. Figure 1 shows some typical types of effigy mounds. Figure 2 shows the area where effigy mounds can be found

Figure 3 shows an index of some of the mounds you can visit near the University of Wisconsin campus at Madison. You will see basic geometry (like 30°, 60°, 90°) as used in modern drafting triangles; along with solar calendar functions and unit distances of layout that relate to 600 ft. and 660 ft. (land measure units found world-wide). Other aspects are self-explanatory.


(By  Patricia  A Arntsen)

The southern part of Wisconsin is often called the “Effigy Mound Region” because most of the Indian mounds of this unique type are found here. However, someone not familiar with the Indian mounds of southern Wisconsin is apt to have some basic questions about mounds in general. This annex asks such questions and attempts to provide some of the answers.

What are “mounds”?

Mounds are earthen structures created by early peoples  around  the world for a variety of purposes.

Why were they built?

The main reasons ancient societies built mounds were: (1) burial, (2) religious or ceremonial functions, (3) directional or other marker, (4) possibly to tell a story and (5) for reasons yet unknown.

Who built the mounds?

Many ancient societies built mounds in the form of a dome  of  earth  in  which  they  interred their dead. These  types  of  mounds  are  called  “conical  mounds”.  Some  peoples, such as the Middle Mississippian Aztalanian Indians, built high pyramidal mounds on which they placed their temples or other structures  related  to  the  practice  of  their  religion.  This type of mound is called “pyramidal” or “temple” mounds. The people of the Effigy Mound Culture built mounds in the shapes of animals and birds as well as conical and linear forms. Figure 1 shows some of these typical shapes.

Who were the Effigy Mound People?

The Effigy Mound Culture flourished mainly in the southern two-thirds of Wisconsin from about 600 AD.  to about 1300 A.D.  They were a  hunting and gathering society,  had a distinctive style of pottery and probably lived in wigwams as other Woodland Indians of the period. The most unique feature of their culture was the effigy mounds.

Where are effigy mounds found?

The vast majority of effigy mounds were built in the southern two-thirds of Wisconsin but extending into Minnesota, Iowa and Illinois. They were usually built on high ground near lakes and rivers and were usually in groups.

What shapes did the Effigy Mound People use?

The most common forms , besides the linear and conical, were water birds or birds of prey (geese, eagles, etc.), amphibians (frogs, turtles, lizards), mammals (panthers, deer, buffalo, bears, etc.) The names assigned to these forms apparently were given by white men who discovered them long after the Effigy Mound People were gone so the names do not necessarily correlate with the intent of the builder.

How were effigy mounds built?

It is not known for sure exactly how the mounds were designed and built. It is known that some mounds were built by first digging out an impression of the form , an intaglio, then filling it in and building it up to form the mound. A cremation site, rock altar, or burial pit was often placed in the position of the head or heart of an animal effigy, in the center of a conical or along the longitudinal axis of a linear mound. The intaglio form may have been lined with clay or sealed with clay after several layers of soil were placed over the base. Some mounds were intricately layered with a variety of soils, some had soil possibly brought in from far distant areas and some were built up of “fill” from a nearby “borrow pit” then sometimes covered with topsoil. In any event, the vegetation on mounds often varied significantly from that nearby and made the mounds more visible during  the growing season.

How big are effigy mounds and how many are in “a group”?

Effigy mounds vary in size but are generally 50 or more feet in length or width and from several inches to about four feet or more in height. The largest existing effigy mound is said to be the bird effigy on the grounds of the Mendota Mental Health Institute with a wingspan of 624 feet. There may be as few as three to as many as over 300 mounds in a group.

Why were effigy mounds built?

It is believed that the mounds were used for burial of important  people in the society  and thereby the mound served the function of a  modern day tombstone.  They also may  have been designed as markers of important places or to tell a story. They probably served important social and religious functions as well.

How many were built? How many remain?

It is estimated that there once were about 20,000 mounds in Wisconsin and that  less than 10% of them remain today. Many of the remaining mounds have been partially destroyed.

How are mounds destroyed?

Mounds are destroyed primarily by cultivation and construction. Grave robbers and pot hunters are also very destructive of mounds and therefore any activity of this sort should be reported to the police.

Why preserve mounds?

Mounds are sacred to the Native American in the  same way the cathedrals of  Europe are important to Euro-Americans. They are ancient burial sites and they are  an important part of out cultural heritage. For these reasons it is important to preserve the mounds.

How can we as individuals help to protect mounds?

Individuals can become aware of where mounds are likely to exist are report locations  of mounds or suspected mounds to the State Historical Society and organizations  such as  the Ancient Earthworks Society and local historic preservation groups for assistance in getting them documented and officially protected under the state burial sites law. ALL mounds are protected under the statute but if mounds are not documented it is difficult to invoke this protection. If you become aware of  the disturbance  of a  mound, contact your local law enforcement department for investigation and prosecution  under  the burial sites . law which forbids any disturbance of a burial site without a permit from the State Historical • Society or any construction within 5 feet of a burial site. All mounds are considered to be burial sites under Wisconsin law.

Ancient Earthworks Society, Inc.

PO Box ll25

Madison, Wisconsin, 53701

(Oct. 1991)