How do I get info?

My great grandpa, Thomas Charles Kennedy, own then sold property in Sherman...but he kept the mineral rights. We dont know any info from there on out...my grandma, Opal Lois Kennedy is now 104 years old and does not remember...please help!

If you live in Grayson co. go to the county clerk office and ask them to show you how to look it up. It's not that hard. it's best to know what years he was doing this but get as close as you can and look in the grantee and grantor books hope this will help