Hello Cynthia,

Have you tried the LDS Library Catalog?

If not, a search for Chickasaw records in MS thru the LDS Library turned up this record set.
http://tinyurl.com/3lkv3cb

From Familysearch
https://www.familysearch.org/
I clicked Catalog, then under the search dropdown... Keywords (beta) For Chickasaw. There were 508 'hits' so you then have to browse the Titles for your record set of interest.

Not sure if you will find your answer here, but this record set might be a starter.

Art