Current market value per acre

My family is preparing to file deeds on minerals my gggrandfather retained in Atoka (240 acres R9E) & Pontotoc(90 acresR4E) counties and need to know the current market value. How is current market determined?

Just a offhand is 5 times the last three years of production. But in Atoka you would want someone to do more in depth research for a fair market price. Try a CPA with oil experience. Good luck