Most people who own property with mineral right assignments to others have it well documented into the titles /property records/ documents related to the property. It can be quite a surprise when mineral right holders let many years go by with no action taken then suddenly exorcise the rights they had which can be upsetting to some because they were able go so so long with out being affected. SO if your buying a home just ask the title searcher to tell you a list of things they search for. If you bought and did not have a title search done your still free to do so If you bought and discover that there is something like mineral right assignment or say a easement for access granted to another over the land you bought then I guess your best bet is to speak to a atty since state law of where the property is located are what will rule and using a atty for advice would be the best choice even if its after the fact so that way you get the best possible advice.