The Daughters of the American Revolution (DAR) Collection contains tombstone inscriptions from some Oklahoma cemeteries. This collection is described in Oklahoma Genealogy. Another important collection is Cemetery Records of Oklahoma, 9 vols. Salt Lake City, Utah: Genealogical Society, 1959-62. (Family History Library book 976.6 V3i; films 824250-52.)
The following book lists many cemeteries by county, and mentions where the records are published:
Pierce, Barbara and Brian Basore. Oklahoma Cemeteries: A Bibliography of the Collections in the Oklahoma Historical Society. Oklahoma City, Oklahoma: Oklahoma Historical Society, 1993. (Family History Library book 976.6 V3p.)
If you are searching for the burials of white and Indian ancestors in any of the 17 northeastern counties, use James W. Tyner and Alice Tyner Timmons, Our People and Where They Rest. 12 vols. Norman, Oklahoma: University of Oklahoma, 1969-78. (Family History Library book 976.6 V3t; vols. 1-6 on film 1290833 items 5-10; vols. 7-10 on film 1290834 items 1-4; vols. 11-12 on film 1888927 items 5-6.) The Family History Library has a master index to these volumes by Jerri G. Chasteen (Family History Library book 976.6 V3t Index).
Inscriptions from graves relocated as a result of the Arkansas River Navigational System are recorded by Madeline S. Mills and Helen R. Mullenax, Relocated Cemeteries in Oklahoma and Parts of Arkansas, Kansas, Texas. Tulsa, Oklahoma: Mills and Mullenax, 1974. (Family History Library book 976.6 V3mm; film 928,142 item 5.)