Conversation so far:
What is Caddoan Mississippian?
a regional variant of the Mississippian culture.
What type of variant of the Mississippian culture?
The Caddoan Mississippian area.
What does it say about Mississippi?
covered a large territory.
Are there any other interesting aspects about this article?
covered a large territory, including what is now eastern Oklahoma.

Question: Any other states?
Self-contained rewrite: Is Caddoan Mississippian covering other states than Mississippi and eastern Oklahoma ?