Where Do I Find Ownership of Mineral Rights in Logan County?

My dad passed in 2011. Last conversation 1980's regarding this was: Leasing / Selling property, but keeping his mineral rights. How/Where can we find the status of this property and mineral rights. My sibling and I are out of state. Property is located in Logan County. Thank you

Logan Co records on line go back to Jan. 1994 . Before that at the court house in Guthrie Ok. I could look online with his name and location of property if you want and see if there is anything .