Finding unclaimed royalties for mineral rights is a fairly simple procedure. It is actually somewhat common for mineral rights royalties to go unclaimed and be held in trust by the state for the owners. Using information you have regarding any family members that might have held mineral rights, you can track down your royalties and file a claim for the money held in trust.
Contact the state of each prospective claim. Most states have websites specifically for claim research. It is a common policy that if the owner is unable to be contacted due to an incorrect address on file, or an inability to find the legal owner after the original owner's death, the mineral royalties are held in trust by the state. If you go to the website for the state in which you believe you have unclaimed royalties, you will be able to search mineral holdings.
Enter as much information as you have about the family members that may have held mineral rights in the state where they lived. You will require, at a minimum, the first and last name of the former owners. It may also be helpful to know where the mineral claim was located, and when your family members owned the mineral rights at that location.
Submit a claim for any unclaimed royalties you find, following the procedure on each state's website and including as much information as you can about your relationship to the person who owned the claim. You may need to have proof of your relationship to the person who owned the claim and your inheritance rights. Once you have submitted your claim online, the state mineral rights department will contact you and may request additional information or proof of relationship.