70 ILCS 1205/3-6
Any territory, within any park district, which (1) is upon the border of the park district, and (2) if disconnected from the park district would not separate any part of the park district from any other part, may be disconnected from the park district, in the discretion of its corporate authorities as follows:
A written petition, signed by the majority of the owners of record of land and the owners of record of more than one-half of the area of land in the territory described in the petition, shall be filed with the secretary of the governing board of the park district, requesting that the specified territory be disconnected from the park district. The petition shall be filed at least 30 days before it is considered by the corporate authorities. The petition shall be accompanied with the certificate of the proper county clerk, or county clerks as the case may be, showing that all park district assessments due up to the time of presenting the petition are fully paid. The corporate authorities may, in their discretion, disconnect the territory from the park district by an ordinance passed by a majority of the members of the governing board.
70 ILCS 1205/3-6