Tryinv to find unclaimed royalties

It belonged to my great-grandmother and I am trying to figure out how they came to be hers in the first place I realized she was married to the great-great-grandson of the original owners of the land but I can’t figure out or proved the ownership line how do I go about doing that and can anyone help me with this. sec1 twn15N range5W

Go to okcountyrecords.com Then go to Custer County. You can put in your grandmother’s name and see where it shows up. Alternatively, you put in a search for 1-15n-15W in the appropriate boxes. Now, the records only go so far back, so if she received her interest prior to 1958, you might find her name in the index, but you can’t look at the instruments. Now, if she acquired her interest from a probate/estate proceeding, that may not have been filed in the Custer County Clerk’s records.