Mineral Rights Ownership Transfer

My wife passed away last year and owned mineral rights located in North Dakota in both Dunn & Slope Counties. She did not have a will but I am her surviving husband. Do I need to legally re-file for ownership transfer for these mineral rights or do they automatically pass on to me? Also, what kind of timeline is normally put on mineral rights...or are they continually passed on to my survivors and other generations thereafter?

I would appreciate any of your comments on this matter.