David Overstreet says he’s older than dirt. Even at 75, it is an odd claim for an archaeologist who has spent much of his life working in very old dirt excavating ancient skeletons and artifacts that are far older than he is. Overstreet says he has probably worked in almost all of Wisconsin’s 72 counties. From sites in the Apostle Islands to Door County, Keshena, Wauwatosa, Elm Grove and many places in between, Overstreet’s explorations and excavations have yielded new evidence and challenged old beliefs and paradigms.

Take the large wooly mammoth skeleton which greets visitors in the entryway of the Milwaukee Public Museum. It’s there in no small part because Overstreet and his team excavated the 14,500-year-old skeleton in the 1990s. It’s called the “Hebior Mammoth”—named for Kenosha County farmer John Hebior, who owned the land on which it was found.

“When you travel south to Chicago on I-43, you see all those cabbage patches along both sides of the highway late in the growing season,” Overstreet says. “Those are old lake beds that have been drained for muck soil agriculture. That’s where these skeletal remains exist. The only reason these ancient animals were preserved was because they had been continuously wet in an anaerobic environment for 15,000 years.”

Many of the bones of the Hebior Mammoth had butcher marks on them, and through radiocarbon dating, analysis of the cut marks and analysis of tools found at the bone pile, there was a concatenation of evidence that allowed Overstreet to date the skeleton. If the mammoth was butchered, that meant that there were people around to do it. The discovery was important. “They made a big deal of it in National Geographic and U.S. News and World Report. That was back in the early ’90s,” Overstreet says.

To dry out the bones of the Hebior Mammoth, Overstreet built crates and used foundry sand that had no organic materials in it. He dried them at his office and lab at Jackson and Water Streets. “We dried them very slowly,” he says. “You have to turn the bones every day. It was miraculous because the collagen in the bone is what we used for the radiocarbon dating. We also recovered a human hair and mammoth hair that was still preserved intact.”

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Decades earlier, Overstreet camped on almost all of the Apostle Islands (before they became a national park) while he did survey work for the National Park Service to identify places where it would build campgrounds or excavate. He once worked for the U.S. Army Corps of Engineers and did an overview of the Upper Mississippi Valley stretching from St. Anthony Falls in Minneapolis down to Prairie du Chien, Wis.

In 1977, Overstreet excavated a large burial site on the Milwaukee County Grounds when the Milwaukee Metropolitan Sewerage District (MMSD) was constructing the deep tunnel. The county grounds is the largest remaining open space in Milwaukee County and home to the confluence of the Menomonee River and Underwood Creek. The MMSD wanted to install a shaft and came across some bones. Overstreet and his team excavated more than 1,300 human skeletons dating from 1840-1950. The site had been a former paupers’ cemetery.

“It was the coroner’s dumping ground,” Overstreet says. “When I started doing the archival research, I found articles in the old Milwaukee Sentinel lamenting the fact that burials were getting kicked up every spring with frost heaving because they were just randomly put in the ground. A lot of them were coroner’s deaths—people who died in house fires or drowned in the Milwaukee harbor. Bodies were just carted out in a wagon after the coroner got through with them and buried in the paupers’ cemetery.”

Bones Tell Wisconsin’s Ancient History

There are probably more old bones awaiting excavation than most people realize. In 1979, a developer found some human bones while grading a new subdivision in Elm Grove and called Overstreet to investigate and excavate the site. The bones were found on the Sisters of Notre Dame property on a little knoll near Underwood Creek. First, Overstreet found a skeleton in which he discovered a stem of a spear point lodged in a lumbar vertebra. After that, his team expanded the excavation and found an infant with elaborate grave goods that had been dressed with red ochre, copper, shells and other materials. Then, they found another burial pit segregated from the knoll that had eight adults who had all met violent deaths—they had been decapitated or dismembered, and some of them had spear points in or between their bones.

“That was the only scientific excavation of a red ochre burial site that has ever been done in this state,” Overstreet says. Red ochre is a pigment that has been used worldwide for burial for thousands of years, and even Neanderthals may have used it. Through radiocarbon dating, the skeletons at the Elm Grove site dated back to 1000 BCE.

Overstreet has worked with the Menominee Tribe in Keshena in northern Wisconsin since the 1990s and has taught at the College of the Menominee Nation. In 1995, some foresters discovered that the floor of the forest was dimpled in a strange way, and Overstreet was once again called in to investigate.

“The whole forest floor was dimpled with these depressions that I recognized right away as storage pits. I also recognized some agricultural ridges,” Overstreet says. He eventually found evidence of many raised agricultural beds in the area. One such bed was larger than 10 acres. The agricultural beds used planting mounds to protect against frost and allowed successful cultivation of a wide variety of crops in a colder climate. In between the ridges were depressions which served to manage moisture and which also provided a system for composting. He discovered that these early farmers did a spring burn which enriched the soil with bio-char. They also may have used sturgeon guts to further enrich the soil. Sturgeon are important to the Menominee, are plentiful in that region and are especially accessible in spring during the spawning season. Through experimentation, Overstreet found that the soil in the raised ridges was greatly enriched as compared to the rather poor soil in the surrounding area, even after hundreds of years of abandonment.

“It turns out that the Menominee were the original organic agriculturalists and had a sustained life-way that I was able to document from 750-1650 CE,” he says. Overstreet looked at several sites on the reservation itself and was able to demonstrate that the early Menominee had pursued organic sustainable agriculture for more than 1,000 years. “For contemporary society, with all its concerns about food sovereignty and climate change, here’s this model.”

Overstreet says his research proved that the Menominee had been settled agriculturalists for hundreds, if not thousands, of years—not nomadic hunter-gathers as was previously believed—and laid to rest earlier scholarship suggesting that the Menominee had only recently inhabited the area that once stretched from the northern tip of Lake Michigan to the Milwaukee River. “The earliest date of these gardens through radiocarbon dating is 750 CE,” Overstreet says. “These are the earliest raised agricultural fields in the mid-continent.”

Excavations Change Native American History

In the past decade, Overstreet has hosted many college interns at the Keshena sites and has run community programs for middle and high school students. One such student, Monea Warrington, grew up in Keshena on the Menominee reservation and met Overstreet when she was 13. She is currently a master’s student in anthropology at UW-Milwaukee and hopes to pursue a doctorate.

Initially, Warrington and her mother took a community class with him. Warrington had taken a vocational interest test a few months earlier, and archaeology emerged as one of her top-five interests. Warrington and her mother found the class fascinating. “For the next few summers, I volunteered to work with Dr. Overstreet’s crew. I really liked the way they were integrating traditional knowledge into what they were doing,” she says. She adds that Menominee history has always been troubled. “I like the way Dr. Overstreet and anthropologists all over are trying to change that. I wanted to be a part of that and help.” Much of Native American history has been lost or obscured, and archaeology provides a means to recover some of it.

While excavating at a site, Warrington once picked up a large shard of pottery that had the fingerprints of the potter on the back of it. “It was so cool to pick up that piece of pottery and to think that the last person that touched this pottery was one of my ancestors a thousand years ago,” she says.

After a long career, Overstreet says he wants to retire soon. The spirit is still willing, but he says he can’t do the heavy physical work associated with archaeology anymore. He retired from Marquette University as director of the Center for Archaeology Research in 2005. In addition to his work with the Menominee Nation, he also is a researcher with the Milwaukee Public Museum. In 2016, Overstreet received a Distinguished Career Award from the Midwest Archaeological Conference. The Menominee Nation presented Overstreet with a blanket, a high traditional honor, at the 2018 Sturgeon Fest for his years of teaching and archaeological work.

“I’m a local product,” he says. “To me, it’s amazing that Wisconsin has such a rich, untapped record of prehistory. I don’t know why anyone would want to go anywhere else if they’re an archaeologist. In my line of work, it doesn’t get much better than to be able to walk out of your front door and go 30 miles away and excavate 14,000-year-old mammoths.”