Hi Ola, I found the following on Sardis Cemetery in the book : Pushmataha Cemeteries Old and New -Second Edition
SARDIS CEMETERY (4-2N-18E )
This cemetery is now an island in Sardis lake. The Corps of Engineeres moved graves and gravestones here from other small graveyards in the area to be inundated . The cemetery was mapped, and a portion was raised by fill then the gravestones were reset.