Listen title search companies are worthless. Not all, but most. The state law governing them is not the best so not entirely their fault. Tennessee only requires that a title search or insurance for the title is only required to go back 30 years for residental searches and 40 years for commerical. Now, if someone purchased the mineral rights in 1981 and the title search didn't happen to see it, they would not be liable for not disclosing this information if something is found latter. Do you homework go down to the court house, run it back as far as you can or have someone do it for you. That being said I would say most of the property maintains there mineral rights, but the rights get sold off in the most strange places. The biggest mineral rights to be had in Tennessee are limestone, phosphate, coal and yes oil to a lesser extent sometimes they are spelled out, sometimes the are very vague. Additionally, easements also pop up in strange places. Loss of mineral rights and easements are not required to be carried forward on a persons deed so they get lost very easy, neither are covenants. If you have an attorney run it back, be sure and ask about mineral rights, easements and covenants and then how far back they cleared the title.