There were more Indian Mounds built in Wisconsin by Native Americans than any other region of North America – between 15,000 and 20,000 – of which about 4,000 remain.

Interest in the remaining mounds is strong.

A standing-room-only audience showed up at the State Historical Society on Feb. 6 for the History Sandwiched in Series to hear former state archeologist Bob Birmingham speak about his new book, Indian Mounds of Wisconsin, Second Edition, published in October 2017 by the University of Wisconsin Press.

Birmingham explained that interest in Indian Mounds wasn’t always so keen. The impetus behind increasing public interest was a new state law in 1985. Wisconsin Act 316 protected all burial sites that do not look like modern cemeteries. The law “upholds the idea that all human burial sites should be accorded equal treatment no matter how old they are or who created them.”

Bob Birmingham

“Prior to this law, native burials were not protected and the law created a lot of questions,” he said. “People called my office and asked: How old are these mounds? What do they mean? Who made them? What were they used for?”

“I thought maybe I should write this down and the first edition of Indian Mounds of Wisconsin came out in 2000.”

Since 2000, Birmingham explained that new research had revealed more information and thus inspired the second edition.

“My colleague, Amy L. Rosebrough, co-author of the book, literally looked at each of the mounds in Wisconsin for her dissertation and wrote the encyclopedia of mounds in Wisconsin. Other types of information have been coming from new technologies,” he said. “More accurate maps are derived from Light Detection and Ranging imaging or LiDAR, which has emerged in the last couple of years.

“LiDAR has the ability to map just the surface of the ground, so it sort of goes through vegetation, so the arrangements and numbers of mounds are very clear and new mounds are being discovered all the time now, which is a great boon for all of us because previously unknown mounds can now be protected. 

“It’s revolutionizing the study of ancient history all over the world. We’re very excited because we are discovering new places which is increasing both our knowledge and emphasizing that more mounds can be protected,” he said.

Birmingham explained that the history of mounds in Wisconsin began with circular mounds, then effigy mounds – in the shapes of animals – and finally platform mounds like the ones at Aztalan State Park in Lake Mills and Trempealeau. All of the mounds are considered sacred by the Ho-Chunk and other native people.

The book goes through the trajectory of the change in native cultures – that populations move through time and become more complex.
Birmingham explained that the first circular mounds showed up around 500-600 AD, known as the Hopewell period. They built mounds with people buried in pits beneath the mound. A good example of this type of mound is the Nicholls Mound near Trempealeau.

“We believe that they were ceremonial mounds that were part of huge ceremonial centers. The mounds also contained trade and exotic items. What they did was dig a big pit for the dead. When filled, they built a mound over it. These were mausoleum mounds with offerings inside such as obsidian from out west, copper from Lake Superior, blades from other areas, pottery, and wood spheres covered with silver. The objects mark the status of a people. These mounds reveal to us complex societies with social structures and elaborate trade networks.”

Indian Mounds at Mendota State Hospital from the book Indian Mounds of Wisconsin, Second Edition. (University of Wisconsin Press)

About 600 AD, the Hopewell Culture collapsed and there is a new movement. This is the start of the Effigy mound period which lasted between 600-1100 AD.

“About 15,000 Effigy Mounds were built in Wisconsin, more than anywhere in the world. This is correlated with a climatic shift. With warmer temperatures and a rise in resources, the population grew,” Birmingham said. “People were all over the Madison area’s uplands, prairies, ponds. We believe that this (population density) created friction and that they developed a common ancestry by creating clans such as bear and thunderbird. By expressing themselves this way they were linking to their ancestry. These clans or spirits played other rolls in society. Thunderbirds give blessings. Bears are associated with earthly order. The different functions organized society and bound people together.”

Birmingham believes that the “mounds were not static monuments or elaborate tomb markers but rather ancestral or otherwise powerful spirits brought into visible existence by rituals at places on the natural landscape where those spirits were perceived to dwell.”

“All effigy mounds have burials within the mounds. The people are buried there probably because they believed they were linked to the ancestors of the clan,” he said.

There are about 100 mounds remaining in the Madison area out of about 1000. Among the most significant are three large groups preserved on the grounds of the Mendota Mental Health Institute on Troy Drive.

In his book, Birmingham describes the Farwell’s Point mound group to include a number of large conical mounds, portions of linear mounds, and bird and water-spirit effigies. The Mendota State Hospital mound group near the main administration building contains some of the finest, rarest and largest effigy mounds preserved anywhere. Included are three large birds, two panthers (one with an unusually curved tail), two bears, a deer, several conical mounds, and one mound of indeterminate shape. One of the bird effigies has a 624-foot wingspan. The deer effigy is unusual because four legs are depicted.

The third group, called the Woodland Shores group, now partly destroyed, depicts mounds with a clear arrangement that models the underlying structure of effigy mound ceremonialism.

“The mounds represent a worldview that the world is divided into three tiers, with each tier having powers useful for human beings – air, earth and water. The Woodland Shores group shows how they viewed the world right there on the earth,” Birmingham said.

Birds, likely thunderbirds, begin the group and are followed by earth mammals such as foxes, wolves, and a bear. The grouping ends with water-related effigy mounds that include long-tailed panthers, turtles and snakes, most of which are oriented toward the lake.
To protect the privacy of patients at the facility, please ask permission at the administration office to tour the mounds.

Platform mounds, like the ones at Aztalan State Park, were built about 900 AD and serve both ceremonial and burial purposes.

Birmingham is also the author of Spirits of Earth: The Effigy Mound Landscape of Madison and the Four Lakes and the coauthor of Aztalan: Mysteries of an Ancient Indian Town. Amy L. Rosebrough is a Wisconsin archaeologist and the coauthor of Water Panthers, Bears, and Thunderbirds: Exploring Wisconsin’s Effigy Mounds.

Indian Mounds of Wisconsin, second edition can be purchased in bookstores or online at the University of Wisconsin Press or