765 ILCS 205/9
Whenever any highway, road, street, alley, public ground, toll-road, railroad, reservoir or canal is laid out, located, opened, widened or extended, or its location altered, it is the duty of the commissioners, authorities, officers, persons or corporations, public or private, laying out, locating, opening, widening, extending or altering the same, to make a plat, showing its width, courses and extent, and making reference to known and established corners or monuments. When the location of a subdivision, lots or parcel within a subdivision, tract, highway, road, street, alley, public ground, toll-road, railroad, reservoir or canal is known either by established corners or adequate, existing records, the monument or monuments shall be located and referenced either by or under the direction of a Registered Land Surveyor at the time such highway, road, street, alley, public ground, toll-road, railroad, reservoir or canal is laid out, located, widened or extended, or its location altered. Suitable permanent monuments shall be reset in the surface of new construction or permanent witness monuments set to perpetuate their location and certified as correct by a Registered Land Surveyor. The plat shall be recorded in the office of the recorder of the county in which the premises are taken or used, or any part thereof, are situated, or in case of land the title to which is registered under "An Act concerning land titles", approved May 1, 1897, as amended, to be filed in the office of the registrar of titles for the county, within 6 months after such highway, road, street, alley, public ground, toll-road, railroad, reservoir or canal is laid out, located, opened, widened, or extended, or the location thereof altered and when any highway, road, street, alley, public ground, toll-road, railroad, reservoir or canal is vacated, the order, ordinance or other declaration of vacation must be in like manner recorded or filed. The recorder or registrar of titles shall not record or register a plat offered for recording or registration after October 1, 1977, unless such plat is at least 8 1/2 inches by 14 inches but not more than 30 inches by 36 inches. Sufficient controlling monuments shall be retained or replaced in their original positions or reference monuments established from original controlling monuments, so as to enable land lines, property corners or tract boundaries to be re-established without surveys based on monuments differing from the ones which currently control the area. Every land surveyor is under a duty to cooperate in matters of maps, field notes and other pertinent records. This Act shall not be construed to alter or affect any law specifically providing for the recording or filing of any plat, or to require the same to be recorded or filed sooner than is so specifically provided; except that any requirements to record or file such plat in any other place than is provided herein do not excuse the parties from complying with this Act. Any party who refuses or neglects to comply with this Section shall be guilty of a petty offense for every month he continues in such refusal or neglect after conviction, to be recovered by an action in the circuit court of the county, in the name of the county, 1/2 to the use of the county and the other 1/2 to the use of the person complaining.
The provisions of this Section shall not apply to a railroad subject to the jurisdiction of the Interstate Commerce Commission or any abandonment of all or a portion of such railroad, except that the provisions of this Section shall apply to the construction of a new line of railroad.
765 ILCS 205/9