A publication of the Archaeological Institute of America
A tasty debate about early humans in Ice Age Wisconsin
Great glaciers came and went across the world's northern latitudes during the 1.8-million-year Ice Age, or Pleistocene period. Waxing, the ice sheets covered Canada and parts of the United States. On the wane, frozen tongues stuck south of the retreating ice. One, the Lake Michigan Lobe, ended in the place we now call southeast Wisconsin. Around 14,000 years ago, as the ice shrank northward, open waters filled its wake. Hardy vegetation--tundra sedges and spruce--sprang up along the frigid shores of glacial Lake Chicago, and great woolly mammoths foraged here. Small numbers of people hardened to cold climates explored this environment, too. Sometimes they feasted on fatty mammoth meat--no mean feat, since they had to hack apart the enormous skeletons with tools made from local, poor-quality chert. When the meal was over they discarded the spent bones and broken knives in giant heaps and moved on.
Today, on the silty borders of the old glacial lake, near the modern city of Kenosha, Wisconsin, archaeologists are digging up snapshots of these prehistoric feasts. There are a dozen known mammoth butchery sites in the United States, but they're all west of the Mississippi. The Kenosha finds are the first-ever east of the river. They're also among a handful of sites that suggest people ventured south of the American ice sheets earlier than previously thought. For decades archaeologists accepted a human arrival date of about 11,000 years ago--but the Kenosha sites date to between 12,200 and 13,500 years before present (B.P.), and the evidence looks pretty good.
The discovery of Kenosha's mammoths began in 1990 when avocational archaeologist Dave Waison overheard old-timers talking about some mastodon bones that used to be on display at the county courthouse. "I got pretty excited," Waison says. "I went to the Kenosha Historical Society and started looking for news clippings to see if I could find out where the bones went. After a few days with no luck, I hit on some articles, and one had a photo of the old Schaefer farm, with Mr. Schaefer holding up a big piece of femur." Then a staffer told Waison she'd found a box of giant bones in the basement. "I went down and opened it up and lo and behold, there they were. Mammoth, not mastodon, and they had some of the most obvious butcher marks I'd ever seen--my heart was pounding and I thought 'This is what everybody's been looking for, east of the Mississippi!'"
Susan Kepecs, an honorary fellow of the department of anthropology, University of Wisconsin-Madison, is a Maya archaeologist and freelance writer and photographer. She thanks James Stoltman, University of Wisconsin-Madison, and Wisconsin State Archaeologist Robert Birmingham.