All mound information, unless otherwise noted, is taken from "The Cahokia Atlas: A Historical Atlas of Cahokia Archaeology", written by Dr. Melvin L. Fowler, Ph.D.(1989).
Not all mounds have names.

Mound 21

Mound 21 is one of the smaller mounds in this east west alignment. Patrick indicates it was a small, conical mound. Visible on some of the recent aerial photographs, it appears today as a very minor contour elevation, one apparently partially covered over by slope wash or disturbed by plowing from Mound 22 to the east.