John: This is a land title issue. An attorney or landman can run the title and determine who has title to the property. Unfortunately, Caddo County does not provide any method to search online. This means that a trip to Anadarko is necessary.
If it was in the name of an ancestor, then you may want to consider filing an affidavit of heirship (AOH). This should ensure that you can be located by leasing agents or landmen. Also, if there is any activity or pooling with the Corporation Commission, you should get notice. However, in order for the AOH to create marketable title in you it must be 1) created correctly in the eyes of the title examiner; and 2) be on file for 10 years with nothing contradictory filed in the interim.
It is most likely that if there is production and royalties to be paid, the company will require a probate. Oklahoma Probate Options