Need capital gains tax Information relating to the sale of mineral rights

I need information on how to find the basis of mineral interest sold by my mother in February of this year. She sold a percentage of all her interests. Some of interest was deeded to her by her parents as a gift. A portion was inherited when her mother died. Do I need an oil and gas lawyer to help me with this or should I turn to a CPA specialist in oil and gas? I have copies of the mineral deeds and leases. I need guidance on what to do to file her taxes. Thanks,

In regard to the interest that was gifted to her, it would be the same tax basis as her parents had at the dated of the gift, less depletion claimed since that date. You should check with who ever prepared their tax returns at the time. (in most cases it would probably be very small.)

In regard to the inherited minerals, the tax basis would be the Fair Market Value of the interest at the date of her Mother's death, less depletion claimed since then. If an attorney assisted with her estate I would check with him.

Thanks for the information. That gives me something solid to work with.