(765 ILCS 515/11) (from Ch. 96 1/2, par. 9211)
    Sec. 11. (a) Surface owners may gain title to severed mineral interests owned by unknown or missing owners under the theory of adverse possession in the following manner and under the following conditions: If the title to any severed mineral interest is vested in an unknown owner or missing owner and the surface owner overlying the severed mineral interest desires to acquire title to it by adverse possession, the surface owner may institute a proceeding in the circuit court of the county in which the severed mineral interest or the major portion thereof lies. The surface owner shall join as defendants to the proceeding all those persons having record title to the severed mineral interest who are unknown or missing and the unknown heirs, successors and assigns of all such persons. The persons named as defendants and who are the unknown or missing owners as defined herein shall stand for and represent the full title and the whole interest of the unknown or missing owners in the severed mineral interest or estate or interest therein. All parties not in being who might have some contingent or future interest therein, and all persons whether in being or not in being, having any interest, present, future or contingent, in the severed mineral interest sought to be acquired, shall be fully bound by the proceedings hereunder. The surface owner shall also join as defendants all other surface owners, if any, who are not plaintiffs.
    (b) There shall be filed a verified petition specifically setting forth the following:
    (1) The legal description of the lands.
    (2) The interest of the plaintiff as a surface owner of the lands.
    (3) The apparent interest of the defendant or defendants in the lands.
    (4) The last known address, residence or whereabouts which plaintiff may have been able to ascertain for each defendant who constitutes an unknown or missing owner and the sources of information which plaintiff has checked in an attempt to locate the present address, residence or whereabouts of each such defendant.
    (5) That plaintiff, upon diligent inquiry, cannot determine the unknown or missing owner defendant's current address, residence or whereabouts and that upon due inquiry, said defendants cannot be found.
    (6) That the surface owners desire to acquire title to the severed mineral interest by adverse possession.
    (7) The petition shall also include as defendants and set forth the apparent interest of all other persons holding a legal interest in the surface estate.
    (c) The defendant or defendants who constitute the unknown or missing owners shall be given notice of the pendency of the action by the clerk of the court by publication to be made in some newspaper published in the county where the action is pending. If there is no newspaper published in that county, then the publication shall be in a newspaper published in an adjoining county in this State, having circulation in the county in which the action is pending. The publication shall contain notice of the pendency of the action, the title of the court, the title of the case, showing the names of the plaintiff and the first named defendant, the number of the case, the names of the parties to be served by publication, the legal description of the lands involved and the date on or after which default may be entered against such party. The clerk shall also, within 10 days of the first publication of the notice, send a copy thereof by mail, addressed to each defendant whose last known address is stated in the petition. The certificate of the clerk that he has sent the copy of the notice in pursuance of this Section is evidence that he has done so. The notice may be given at any time after the commencement of the action, and shall be published at least once in each week for 3 successive weeks. No default or proceeding shall be taken against any defendant unless the first publication was at least 30 days prior to the time when the default or other proceeding is sought to be taken.
    (d)(1) If in any action there are persons who would be unknown parties as defined in Section 2-413 of the Code of Civil Procedure, they may be made defendants to this action in the same manner and with the same effect as provided in the Code of Civil Procedure. Said defendants shall be given notice of the pendency of the action by publication as provided herein.
    (2) The court shall appoint a guardian ad litem for any party to the proceeding who is a ward and who is not represented by a guardian.
    (3) If it appears that any person not in being upon coming into being is or may become or may claim to be entitled to any interest in the property, the court shall appoint some competent and disinterested person as guardian ad litem to appear for and represent such interest in the proceeding and to defend the proceeding on behalf of the person not in being, and any judgment or order rendered in the proceeding is as effectual for all purposes as though the person were in being and were a party to the proceeding.
    (e) If any defendant who constitutes an unknown or missing owner answers or otherwise appears personally, and the court finds that he is the unknown or missing owner of the severed mineral interest, the court shall enter an order determining the interest of such defendant and he shall be dismissed from the action. The appearance by a guardian ad litem appointed pursuant to subsection 11(d)(2) or subsection 11(d)(3) of this Section shall not be deemed a personal appearance within the meaning of this subsection (e). As to all other defendants and after compliance with the notice requirements provided herein, the court shall take evidence and take testimony as to the matters set forth in the petition. If upon taking evidence and hearing testimony it appears that all material allegations of the complaint are true and that there has been compliance with the notice provisions herein provided, the court shall enter a judgment that the owner of the surface estate and his heirs, successors and assigns, is from the date of the judgment exercising presumptive adverse possession of the severed mineral interests by reason of his ownership.     (f) The plaintiff shall cause a report of the proceedings of the evidence received and testimony taken at the hearing on the petition to be filed and made a part of the case record.
    (g) If, (1) the owners of the severed mineral interests remain unknown or missing for a period of 7 years from the date of the judgment to the effect that the owner of the surface estate overlying the severed mineral interest is exercising presumptive adverse possession over the same or, (2) the owners of the severed mineral interest remain unknown or missing for a period of one year from the date of the judgment to the effect that the owner of the surface estate overlying the severed mineral interest is exercising presumptive adverse possession over the same and the severance took place more than 20 years prior to the date of the filing of the original petition, the plaintiff or his then successor in title shall file a motion with the court renewing or supplementing the allegations of the original petition and particularly containing allegations relative to the last known address, residence or whereabouts which the plaintiff may have been able to ascertain for each defendant who constitutes an unknown or missing owner and the sources of information which plaintiff has checked in an attempt to locate the present address, residence or whereabouts of each defendant since the date of filing of the original petition. The motion shall also contain an allegation that the plaintiff, upon diligent inquiry cannot determine the defendants' current address, residence or whereabouts and that upon due inquiry said defendants cannot be found. Notice of the hearing upon the motion shall be given in the same manner as notice of the hearing upon the original petition. If any defendant who constitutes an unknown or missing owner answers or otherwise appears in response to the motion, the court shall enter an order determining the interest of such owner and shall dismiss the action as to such defendant. As to all other defendants and after compliance with the notice requirements provided herein, the court shall again take evidence and hear testimony as to the matters set forth in the original petition and in the motion. If upon taking evidence and hearing testimony it appears that all material allegations of the original complaint and of the motion are true and that there has been compliance with the notice provisions herein provided and payment by plaintiff of all taxes legally assessed on such severed mineral interests, the court shall enter a judgment declaring that the severed mineral interests are null and void due to adverse possession by the surface owner and that fee title to such severed mineral interests is vested in such surface owner. The court or such other officer appointed by the court shall then convey to the surface owners in proportion to their record interests by recordable instrument the unknown or missing owners' interest in the severed mineral interests.
    (h) At any time subsequent to the entry of the judgment that the surface owner is exercising presumptive adverse possession of the severed mineral interests and prior to the entry of a judgment declaring the interest null and void, the owner of the severed mineral interest may intervene in the proceeding and upon notice to all parties who have appeared in the case as the court directs present proof of his ownership of the severed mineral interest. Upon a finding by the court that such intervenor is the owner of said severed mineral interest and upon payment to the plaintiff of all real estate taxes upon said severed mineral interest theretofore paid by the plaintiff and such reasonable attorney fees and costs as the court may allow, the court shall enter an order determining the interest of such owner and shall dismiss the action as to such intervenor.
(Source: P.A. 83-571.)