I was in the area a week ago and drove the vicinity based on the map in the Civil War Sites Advisory Commission Report on the Nation's Civil War Battlefields update which was done about three years ago.

It shows the core battlefield area to be south of 96th. I drove east on 86th and took roads both north and south of 86th just west of the creek. Neither allowed me to go very far. Was I in the general area of the battlefield.

That map also seems to indicate that after the battle Opothleyahola's people traveled northward and then northwest toward Chustenahlah.

The map can be found here:
http://www.cr.nps.gov/hps/abpp/CWSII/CWSACReportOklahomaUpdate.pdf