"For example those Keechais who stole Noah Smithwick's horses outside of Bastrop were technically Pawnees."
Only if by linguistics! Keechis were Caddoan..... Just like the Anadarko, Adai, Bedias, Nebadache, Nachito, and Neche etc........ They were recorded early on by both French and Spanish.
I believe Pawnee's were once refered to as the plains Caddo and were supposedly associated with the Quapaws of SE Arkansas. Another Caddoan linguistics group member.
I also believe this to be true. I was born and raised in Caddo Co. Oklahoma nestled among the Keechi hills south of Anadarko. The Keechis are a small group of unique hills a little north and east of the Wichita Mts. Blackjack oak country on the edge of the plains.
