When folks find they own minerals they had no idea about, it is typically from an inheritance. Perhaps a grandparent owned some minerals that passed to your mother. If you have other relatives that are receiving the same royalties, perhaps they would know which family member acquired them and when. To find out, exactly, what is owned, you would need to dig through the deed records in Pecos County (or an online deed records website). It can be tough if you don’t know “who” you’re looking for, but I would guess it was a relative. Somewhere in the records should be one (or more) deeds showing who received what, when, and where. A landman could do this for you, but it would be expensive and could out-cost the value of the “micro” interests, though maybe not. But, if you want to try it yourself, I’d start on a site like Texas File and see what you can dig up there.
I have been busy caring for my 90yo father who has dementia and just now logged back into this site and saw your response - thank you!
It’s likely that the mineral rights were inherited from her father’s family, who settled in Pecos County in the late 1800’s. Her grandfather and father were both attorney’s who accepted fractional mineral interests as payment for legal services. We have record of a dozen or so properties, but this one was not in the paperwork she received when her father passed. But this new discovery does make me want to do some in-depth research to find out what else there might be. Thanks again for taking the time to respond!