Columbia subject headings:
Harvard subject headings:
Illinois--Antiquities.
Indians of North America--Illinois--Sangamon River Valley--Antiquities.
Land settlement patterns, Prehistoric--Illinois.
Sangamon River Valley (Ill.)--Antiquities.
Princeton subject headings:
Illinois--Antiquities.
Indians of North America--Illinois--Sangamon Valley--Antiquities.
Land settlement patterns, Prehistoric--Illinois.
Sangamon River Valley (Ill.)--Antiquities.