Imagine a flood so large that it would wipe out entire towns and cities that sit on the banks of the Mississippi River. That isn’t something today that seems very reasonable, but new research is showing that it might have been just what happened to end the Cahokia civilization. This wasn’t just any community of Native Americans, either.

This was the largest Native American civilization in the U.S., and it was completely wiped out by this massive flood. The Cahokia civilization sat just north of Mexico and first popped up around 600 A.D. It peaked between 1000-1200 A.D., before then being wiped out by the massive flood that scientists are just learning about.

The interesting part about the demise of the Cahokia civilization is that even as it happened around 1400 A.D. there was a 6-mile patch that almost instantaneously became vacant. For a civilization like the Cahokia, which had thrived for hundreds of years, this quick exit was surprising. Even more surprising was their weakness to this type of event, despite the fact that they largely controlled the economic world from the Mexican border all the way to the Great Lakes. For a civilization with as much control and influence as they had, it’s interesting to see that it simply dissipated with virtually no warning.

The study was published in the Proceedings for the National Academy of Sciences, and it revealed that outside this window where the Cahokia civilization thrived, there were frequent floods and challenging circumstances to live. Ultimately, a flood was what drove this civilization out of the region. It doesn’t look like the Cahokia civilization went down without evolving, however. In this situation, the team found that the Cahokia civilization took steps to remedy their issues to that point.


Sissel Schroeder, a professor of anthropology who worked with the researchers said, “We see some important changes in the archaeology of the site at this time, including a wooden wall that is built around the central precinct of Cahokia.” She went on to point out that, “There are shifts in craft production, house size and shape, and other signals in material production that indicate political, social and economic changes that may be associated with social unrest.”

Originally, the theories were in place that drought was what caused the demise of the Cahokia civilization. This is interesting because it gives a completely different account of what likely attributed to their demise. Samuel Munoz the study’s lead author pointed out, “We are not arguing against the role of drought in Cahokia’s decline, but this presents another piece of information.”

He went on by pointing out that, “It also provides new information about the flood history of the Mississippi River, which may be useful to agencies and townships interested in reducing the exposure of current landowners and townships to flood risk,” which shows just how important and how diverse studies like this can be for having additional resources to explain climate trends.