70 ILCS 1205/3-2
Territory adjoining any Park District, or separated therefrom only by a river, stream, drainage canal or ditch or other body of water, street, alley, roadway, highway, toll road, or railroad, may be annexed to and become a part of such district in the manner following: The board of any park district may initiate the proceedings by enacting an ordinance expressing its desire to annex such territory or any 100 or more legal voters residing within the territory proposed to be annexed, may petition to initiate such annexation proceedings. Such ordinance or petition shall be filed with the Clerk of the Circuit Court of the County wherein such Park District or greater or greatest portion thereof lies, which ordinance or petition shall set forth the name of the Park District to which annexation is proposed, define the limits of the territory proposed to be annexed, and request the Judge of the Circuit Court to order the question initiated by the petition or ordinance to be submitted to the legal voters of such Park District and of the territory proposed to be annexed; provided, however, if the legal voters residing within the territory proposed to be annexed are fewer than 200 in number, a majority of such legal voters, may petition in like manner as above; provided, further, that if there are no legal voters residing within the territory proposed to be annexed a majority of the adult owners of record of lands within the territory proposed to be annexed, and who represent a major portion in area of land within such territory, may petition in the manner above provided; provided further, that no tract of land exceeding 20 acres in area shall be included in such petition or ordinance without the written consent of the owners of record unless the same (1) is subdivided into lots or blocks, (2) is bounded on 3 sides by lands subdivided into lots or blocks, or (3) is used for commercial or industrial purposes. The petitioners or corporate authorities, as the case may be, shall give notice of the annexation petition or ordinance, as the case may be, not more than 45 or less than 30 days prior to the passage of such ordinance or the filing of the petition with the Clerk of the Circuit Court. This notice shall state that a petition or ordinance for annexation, as the case may be, will be filed and give the substance of the petition or ordinance, including a description of the territory to be annexed, the date of filing and the name of the annexing park district. This notice shall be given by publishing a notice once in a newspaper published in the annexing park district, or, if no newspaper is published in the annexing park district, then in a newspaper with a general circulation within the annexing park district. A copy of this notice shall be filed with the clerk of the annexing park district. Upon the filing of such petition the court shall determine its validity and if it is in conformity with law shall order said proposition submitted to referendum as provided in Section 3-3 hereof.
70 ILCS 1205/3-2