(A) (1) Whoever commits any of the following commits a misdemeanor:
(a) Knowingly and without lawful authority enters or remains within or on a building;
(b) Enters upon the land of another, after receiving prior to the entry notice from the owner or occupant that the entry is forbidden;
(c) Remains upon the land of another, after receiving notice from the owner or occupant to depart;
(d) Enters a field used or capable of being used for growing crops, an enclosed area containing livestock, an agricultural building containing livestock, or an orchard in or on a motor vehicle (including an off-road vehicle, motorcycle, moped, or any other powered two-wheel vehicle) after receiving, prior to the entry, notice from the owner or occupant that the entry is forbidden or remains upon or in the area after receiving notice from the owner or occupant to depart.
(2) For purposes of this division (A), this section shall not apply to being in a building which is open to the public while the building is open to the public during its normal hours of operation, nor shall this section apply to a person who enters a public building under the reasonable belief that the building is still open to the public.
(B) (1) A person has received notice from the owner or occupant within the meaning of division (A) if the person has been notified personally, either orally or in writing, including a valid court order as defined by ILCS Ch. 725, Act 5, § 112A-3 granting the remedy in ILCS Ch. 725, Act 5, § 112A-14(b)(2), or if a printed or written notice forbidding such entry has been conspicuously posted or exhibited at the main entrance to the land or the forbidden part thereof.
(2) Subject to the provisions of division (B)(3) of this section, as an alternative to the posting of real property as set forth in division (B)(1) of this section, the owner or lessee of any real property may post the property by placing identifying purple marks on trees or posts around the area to be posted. Each purple mark shall be:
(a) A vertical line of at least eight inches in length and the bottom of the mark shall be no less than three feet nor more than five feet high. Such marks shall be placed no more than 100 feet apart and shall be readily visible to any person approaching the property; or
(b) A post capped or otherwise marked on at least its top two inches. The bottom of the cap or mark shall be not less than three feet but not more than five feet, six inches high. Posts so marked shall be placed not more than 36 feet apart and shall be readily visible to any person approaching the property. Prior to applying a cap or mark which is visible from both sides of a fence shared by different property owners or lessees, all such owners or lessees shall concur in the decision to post their own property.
(c) Nothing in this division (B)(2) shall be construed to authorize the owner or lessee of any real property to place any purple marks on any tree or post or to install any post or fence if doing so would violate any applicable law, rule, ordinance, order, covenant, bylaw, declaration, regulation, restriction, contract, or instrument.
(3) Any owner or lessee who marks his or her real property using the method described in division (B)(2) of this section must also provide notice as described in division (B)(1) of this section. The public of the State of Illinois shall be informed of the provisions of division (B)(2) by the Illinois Department of Agriculture and the Illinois Department of Natural Resources. These Departments shall conduct an information campaign for the general public concerning the interpretation and implementation of division (B)(2). The information shall inform the public about the marking requirements and the applicability of division (B)(2) including information regarding the size requirements of the markings as well as the manner in which the markings shall be displayed. The Departments shall also include information regarding the requirement that, until the date this division becomes inoperative, any owner or lessee who chooses to mark his or her property using paint, must also comply with one of the notice requirements listed in division (B)(1). The Departments may prepare a brochure or may disseminate the information through agency websites. Non-governmental organizations including, but not limited to, the Illinois Forestry Association, Illinois Tree Farm and the Walnut Council may help to disseminate the information regarding the requirements and applicability of division (B)(2) based on materials provided by the Departments. This division (B)(3) is inoperative on and after January 1, 2013.
(4) Divisions (B)(2) and (3) of this section do not apply to real property located in a municipality of over 2,000,000 inhabitants.
(C) This section does not apply to any person, whether a migrant worker or otherwise, living on the land with permission of the owner or of the owner’s agent having apparent authority to hire workers on the land and assign them living quarters or a place of accommodations for living thereon, nor to anyone living on the land at the request of or by occupancy, leasing, or other agreement or arrangement with the owner or the owner’s agent, nor to anyone invited by the migrant worker or other person so living on the land to visit him or her at the place that person is so living upon the land.
(D) (1) A person shall be exempt from prosecution under this section if the person beautifies unoccupied and abandoned residential and industrial properties located within any municipality.
(2) For the purpose of this division (D), UNOCCUPIED AND ABANDONED RESIDENTIAL AND INDUSTRIAL PROPERTY means any real estate:
(a) In which the taxes have not been paid for a period of at least two years; and
(b) Which has been left unoccupied and abandoned for a period of at least one year.
(3) For the purpose of this division (D), BEAUTIFIES means to landscape, to clean up litter, or to repair dilapidated conditions on, or to board up windows and doors.
(E) No person shall be liable in any civil action for money damages to the owner of unoccupied and abandoned residential and industrial property which that person beautifies pursuant to division (D) of this section.
(F) This section does not prohibit a person from entering a building or upon the land of another for emergency purposes. For purposes of this division (F), EMERGENCY means a condition or circumstance in which an individual is or is reasonably believed by the person to be in imminent danger of serious bodily harm or in which property is or is reasonably believed to be in imminent danger of damage or destruction.
(ILCS Ch. 720, Act 5, § 21-3) Penalty, see § 130.99