Okla. Stat. tit. 18 § 489
That any receiver, assignee, guardian, trustee, executor, administrator or other fiduciary, required by law or the order of any court or judge, to give a bond or other obligations as such, may include as a part of the lawful expense of executing his trust, such reasonable sum paid a company authorized under the laws of this state so to do, for becoming his surety on such bond as may be allowed by the court in which or a judge before whom, he is required to account, and when any such bond is signed by a surety company as surety, the penalty must not be in excess of the value of the personal property and the probable value of the annual rents, profits and issues of real property, which are likely to come into the hands of such receiver, assignee, guardian, trustee, executor, administrator or other fiduciary. But when real estate is to be sold an additional bond shall be required in amount equal to the probable value of such real estate.
Okla. Stat. tit. 18, § 489