Can’t find proof of mineral deed online

We inherited 4 mineral interests in Pecos County, Texas and 1 mineral interest in Wichita County Texas, but I can’t find the Deed online. These were bought by my maternal grandfather in the 1920’s. My mother’s sister deeded her ownership to her kids before she died and I can find that online, but my mother never did that. What do I need to send to County Clerks offices to prove ownership and have info on file for interested companies to contact us. Thanks for any and all help!

You could file an affidavit of heirship or copy of probate if you filed. If it was not in trust, and she did not deed it to you before death, you’ll need to file for probate. If she signed a deed prior to, you just need to file it.