Valley County, MT - Need to find out lease / production status and valuation for 340 acres

As executor/heir for an estate with 340 acres of mineral interests in Valley (not Toole) County, I need to find out status of leases / production and get an appraisal on the following parcels - A) Township 26, Range 45E, Sec 12: E2NE4SW4 and B) Township 27, Range 43E, Sec 16: S2. Any suggestions on how to find out or who to contact?