Who will be entitled to the new found money if the will has already been closed and settled?

You do not indicate relevant details. I assume the estate for your mother was completed. However, estates can be re-opened if needed. Was the will drafted by an attorney? Did it contain a "residue" clause if so? Also, if there are oil and gas rights then those may be connected with ownership of land. Who owns the land? Have the mineral rights been severed or are they still a part of the land? Who owns the land and how is it titled? That may give you a clue. What does mother's death have to do with grandmother? Is grandmother still alive? Where did mother mother live at the time of her death? What about grandmother if she died too? Your question presents numerous scenarios and without reviewing the relevant documents its very difficult to answer. Assuming mother died prior to grandmother, mother's assets are distributed as per mother's will. If grandmother is also now deceased, did she have a will? If so, what does it say? If the land is bequeathed to a beneficiary then that beneficiary would get the mineral rights. If there is no will or no mention of mineral rights, then grandmother's interest will pass to her heirs under the intestacy law, which would be her children. Since mother died, mother's share will pass to mother's children. Thus, grandmother's 3 living children and mother's children would inherit and mother's children would divide her 1/4 share up equally. However, this assumes further that grandmother owned the land as well as the mineral rights. This is not always the case and review of the deeds would be necessary as well as to do a title search of the property to ensure that the mineral rights were not separated and sold to someone else. If so, then that person or entity would own the mineral rights. If mother died after grandmother then mother's share of any inheritance from grandmother would pass as per mother's will. If there is a residue clause, it would pass as per the residue clause. If there is no residue clause, then it would pass as per the intestacy laws of the state where she lived at the time of her death to her spouse, if any, and children. As I said, it is impossible to know which of these scenarios will apply without review of the actual documents. My advice would be to get the deed to the real property and get the will for mother and grandmother (if she is deceased) and take to a probate lawyer in the county where the estates were probated. You may also need a real estate lawyer in PA who practices in the county where the land is located to do a title search and make sure that the mineral rights are owned by the same person who owns the surface rights and title to the land. Pay the probate lawyer to review this information and advise as to who gets what.