765 ILCS 215/3
Upon the filing of proper petition and proof of due notice as aforesaid, the said court shall appoint a commission of three surveyors, entirely disinterested, to make said survey, who shall proceed to make said survey and report their proceedings to the said court, as soon as may be accompanied by a plat and notes of said survey; said commission of surveyors shall be authorized to administer an oath, and take the evidence of, and incorporate the same with their survey, of any person who may be able to identify any original government or other legally established corner or witness thereto, or government line, tree or other noted object, and all stone corners or other monuments that have been in existence over twenty years, and recognized as original government corners by the adjoining proprietors.
765 ILCS 215/3