A map showing the geographical distribution and frequency of <a href="https://en.wikipedia.org/wiki/Mill_Creek_chert" class="extiw" title="en:Mill Creek chert">en:Mill Creek chert</a> finds at <a href="https://en.wikipedia.org/wiki/Mississippian_culture" class="extiw" title="en:Mississippian culture">en:Mississippian culture</a> sites.
Herb Roe, www.chromesun.com
CC BY-SA 3.0
<span class="int-own-work" lang="en">Own work</span>