Posted by Unlawful Conduct on Public Property
It is unlawful for any person to enter or remain in any public building or on any public property or to conduct himself or herself in or on the same in violation of any order, rule, or regulation concerning any matter prescribed in this subsection (1), limiting or prohibiting the use or activities or conduct in such public building or on such public property, issued by any officer or agency having the power of control, management, or supervision of the building or property.
Class 3 Misdemeanor:
MIN Fifty dollar fine
MAX 6 months / 750 dollar fine or both
Regarding the business of writing “Jesus” habitually and repeatedly in huge letters in the snow the applicable statutes are here (Definitions), here (Defacing Property), and here (Bias-Motivated Crimes). Of course it is illegal.