Saw the news item the other day regarding reintroducing the American Bison to open lands on the Blackfeet reservation in Montana. Apparently, bison from the reservation were transported to Canada about a century ago to recreate a herd north of the boarder, and now the folks up in the Great White North are returning the favor to the Blackfeet people. Naturally, the ‘sagebrush rebellion’ folks are against it, but a few of the giant animals are already roaming their former range.
Thoughts of bison naturally turn to the Great Plains and the eastern slope of the Rockies, since that’s where the giant herds lived that so impressed early travelers and settlers. But we had bison right here on the tallgrass prairies and in the woods east of the Mississippi just as they did west of the river. Granted, the eastern herds weren’t as vast as the western herds, but at one time, there were a lot of bison around these parts.

A detail from Hennepin’s 1687 map of the Mississippi River recognizes the importance of bison to the lives of Native People. (Library of Congress)
In fact, on one of the earliest maps depicting northern Illinois, our Fox River (as distinct from the Fox River of Wisconsin that empties into Green Bay) is labeled “R. Pestekouy.”
Pestekouy was reportedly the word for bison in the tongue of the resident Native Americans who spoke the Algonquian family of languages. So the name of the river suggests American Bison were probably fairly common along its banks.
Although the upper Illinois River Valley and its tributaries comprise a tiny fraction of the huge map (measuring 6 x 4.5 feet, it was drawn by the official cartographer of New France, Jean Baptiste Louis Franquelin), it is perhaps the earliest and most accurate of the maps produced during the 17th Century era of exploration of the lower Great Lakes.
The history of bison in Illinois has been of interest to historians and archaeologists for generations—and in dispute for almost the entire time. The attempt to chronicle that history and fit it into the history and prehistory of the state has been a puzzle that has become much more clear in recent years.
The last wild bison in Illinois was reportedly killed about 1808, so by the time the earliest settlers arrived in northern Illinois, the huge grazing animals had been gone for two decades or so.

This 1855 engraving gives an idea of how the hunters of the Illinois Confederacy may well have hunted bison during the winter here in Illinois.
With the question of when bison disappeared from Illinois documented, the state’s early historians began wondering how long the animals had been in the state before they were eradicated. In the late 19th Century, the new science of archaeology began to be applied to the most obvious (and sometimes spectacular) of Native American remains in Illinois—the thousands of mounds that dotted the state. Given the importance of bison to the tribes then still living on the Great Plains west of the Mississippi, the state’s early historians figured that certainly the Indians who occupied Illinois up to the era of colonization would also have been intensive consumers of the animals. So imagine their surprise when a vanishingly small number of bison remains were discovered through the years during excavations of mounds and, later, village and other habitation sites.
Those findings seemed to clash with accounts left by early French explorers who visited Illinois during the late 1600s, and who reported that bison were a major food source for local Indians who, they reported, conducted large, organized bison hunts twice yearly.
So the question loomed: How could bison be such a major factor in the culture of Indians during the Historic Period when physical evidence for them in Native People’s habitation sites seemed so rare?
After surveying the archaeological evidence collected during the previous several decades, John W. Griffin and Donald Wray concluded in a 1945 article in the Transactions of the Illinois State Academy of Science, “Bison in Illinois Archaeology,” that bison did not arrive in Illinois until around 1600. They surmised that extreme drought conditions west of the Mississippi might have driven bison to seek better grazing east of the river. While that explanation seemed to fit the facts as they were then known, both historians and archaeologists remained uncomfortable with it.

The range of the American Bison is mapped above, with the plains bison in darker brown and the larger woods bison in lighter brown. The lightest color denotes the range extent of Ice Age bison.
It was good they were uncomfortable because, as it turns out, the very archaeological evidence—or lack thereof—they relied on to make their determination ended up misleading Griffin and Wray.
Since 1945, work has continued to understand Illinois’ prehistory, including numerous excavations of habitation sites, as well as archeological and paleontological work at a number of non-village and non-habitation sites. As that all moved forward, more and more evidence began to accumulate that herds of bison had been present in Illinois for thousands of years before 1600.
Newer, more accurate scientific dating techniques for animal remains and the accumulation of ever more knowledge concerning Illinois during prehistoric times began leading researchers towards the idea that not only did bison roam Illinois well before historic times, but that they were also likely important sources of food for thousands of years.
Then in 2005, solid physical evidence for that was uncovered at the Lonza-Caterpillar Site along the Illinois River near Peoria. Archaeological excavations at the site had begun in 1996 and had uncovered several bison skeletons, along with those of elk, deer, and other animals apparently intermixed with evidence of human habitation, including cooking pits. Testing suggested Native Americans had occupied the site, off and on, for some 4,000 years.
As excavation continued at the site during the summer of 2005, researchers from the Illinois State Museum uncovered a bison skeleton with an embedded stone projectile point, clearly indicating hunters had harvested it. A bone in a second set of bison remains had a bit of chert, apparently from a broken projectile point, embedded in it as well. Both sets of bones were scientifically dated and suggest humans were for sure hunting bison in Illinois between 450 and 250 B.C.
Coupled with an increasing number of finds of bison remains, including remains of at least two individual animals discovered during silica sand mining operations near Ottawa that were dated to nearly 6,000 years ago, it seems that bison probably inhabited Illinois more or less continuously from the end of the last extension of glaciers into the state until they were exterminated in the first decade of the 19th Century.

Prairie bison once roamed virtually all of Illinois. The last wild bison was killed in 1808. They have now been reintroduced by both commercial breeders and in such places as on the grounds of Fermi National Laboratory in Batavia.
And that prompted historians, paleontologists, and archaeologists to undertake a complete reexamination of those widely accepted conclusions reached back in 1945 by Griffin and Wray.
Finds right here in Kendall County helped nudge those conclusions along after the numbers were plugged into scientific studies.
Among those finds was, in the first decade of the 20th Century, a trove of bison bones here in Seward Township on John Bamford‘s farm. Then in the late 1980s, another bison bone was discovered at the Jensen Site in what was found to be an ancient cooking pit on Dr. Lewis Weishew’s former property in Oswego.
And Kendall County wasn’t unique in that respect. Bison bones kept popping up in places they shouldn’t have—if Griffin and Wray’s hypothesis was correct—all over Illinois. By the late 1990s, R. Bruce McMillan, then the director of the Illinois State Museum, was curious enough to begin looking at the subject anew. He figured one good way to get an idea of bison in Illinois would be to survey the state’s museums—large and small—to see just how many bison remains had been discovered and where they were found.
As part of his study, McMillan and Dr. Bonnie Styles of the Illinois State Museum staff visited the Little White School Museum in Oswego in June 2000 to see the bison remains on exhibit there, including a portion of a rear leg bone discovered at the Jensen Site; a more complete bison leg bone found in the Fox River just above the mouth of Waubonsie Creek; and a bison tooth found in the creek itself. All three were submitted to Dr. Michael Finnegan of Kansas State University for positive identification as bison remains. Dr. Finnegan dated the Jensen Site bone to between 1200 and 1400 A.D., hundreds of years before Griffin and Wray suggested they’d arrived east of the Mississippi.
So if bison were here in Illinois, and quite common at that, what accounts for the rarity of bison bones in early Indian habitation sites? According to McMillan, the lack of bison evidence is not evidence of a lack of bison.
Something scientists, with a bit of humor, have dubbed the “schlepp effect” kicks in with bison, animals too large to easily haul to a village site in one piece after killing. Instead, he suggested, bison were butchered at kill sites and the meat, not the whole carcass, was hauled (“schlepped”) to village sites. And in fact, French accounts during the early historic period in Illinois attest to that. Bison bones left exposed on the Illinois prairie quickly deteriorate unless quickly covered like those at the Lonza-Caterpillar Site, thus was their very existence cloaked.
It appears bison reached their largest population in Illinois during the early historic period due to a variety of factors including the decimation of Native American tribes by imported European diseases and inter-tribal warfare. The introduction of firearms and the demand for bison hides then led to the animals’ eradication east of the Mississippi. In 1704, for instance, a single French tannery established near the mouth of the Ohio River reported shipping more than 12,000 bison hides down the Mississippi River to New Orleans.
This story is a great illustration of what science is really all about. It is not well understood by many of us laypeople that scientists are always ready to rethink their conclusions—if and when something better comes along to explain whatever phenomena they’re studying. The key is, it really has to be better, scientifically, and provable in order to overturn a currently accepted theory.
If you’re interested in how 50 years of conventional scientific wisdom concerning bison in Illinois was turned on its head, get a copy of Records of Early Bison in Illinois by R. Bruce McMillan—it’s still available used on Amazon.com.