70 ILCS 1205/3-10
Whenever a Park District operating within territory predominately in a city or village or 2 or more cities or villages would become coterminous or nearly coterminous with such city or village or 2 or more cities or villages upon the annexation of additional territory within such municipalities but not incorporated within a park district, such Park District may annex such additional territory by the passage of an ordinance to that effect. However, no territory may be annexed under this Section more than one year after it has first been included in such municipality unless such territory so annexed is 120 acres or less.
The ordinance shall describe the territory annexed and a certified copy thereof together with an accurate map of the annexed territory shall be filed in the offices of the county clerk and recorder of each county in which the annexation takes place.
70 ILCS 1205/3-10