The only method that I know of is to conduct what is called a grantor/grantee title search with the Fresno County Recorder’s Office. You can trace title using your mother and/or father’s name to see if you can find documents that show if you had mineral rights and what may have happened to them.
A professional landman can conduct such searches for you. This is their expertise, among other title issues. Such a search, however, would be costly given that you have nothing to go on but your name.
Some of this work can be conducted online via the Recorder’s office.
Good luck!