How Do I Prove Life Estate in Minerals has Terminated?

We purchased land in Texas which the seller/grantor retained a life estate in 50% of the minerals for herself and her husband. Both are now deceased. I have no family relationship with the grantor so cannot obtain a copy of their death certificates. Both the seller/granter and I entered into an oil & gas lease a few years ago. I ratified the seller/grantor’s lease. How do I prove the life estate has terminated and that I own 100% of th minerals and what do I need to file of record with the county real estate records? Many Thanks.

You will need the remaindermen of the estate to sign something that it has been terminated.

File an affidavit stating that they have died, and any information you have such as date of death, location, etc. that way it will be in the records for future companies. Send a copy of the files copy to your current lessee

The Social Security Death Index is open online to anyone, might be of help there also.