Okla. Stat. tit. 58 § 385b
To obtain an order for mortgaging such real estate for the purpose and under the provisions hereof, the administrator or executor must present a verified petition to the district court, or to the judge thereof, setting forth a description of the property, real and personal, on hand and undisposed of, the legally established debts outstanding and unpaid, the legally ordered family allowance due and unpaid, if any, the amount of the charges and expenses of administration, the names and addresses of the heirs, devisees and legatees of the decedent, and the specific reason why it will be to the best interest of said estate to mortgage, rather than to sell, such real estate or a part thereof. Such petition to mortgage shall not be filed and the authority therefor shall not be given or order therefor made, until after the time within which to present claims has expired. Such authority shall not be given or order made therefor, and no mortgage on any real estate shall be made, given, executed or delivered under the provisions hereof, for an amount in excess of two-thirds (2/3) of the appraised value thereof, as established by an appraisal made by three disinterested citizens of the county within one (1) year of the time of making such order to mortgage.
Okla. Stat. tit. 58, § 385b