If you're talking about Glenridge near Montclair and Bloomfield this is from the municipal code. " No person shall in any park property damage,cut,carve, or dig in or otherwise disturb grass areas." Playgrounds are usually OK in the towns that have this in the code. Most of the towns in this area have the same thing in the code so I usually ask a police officer what they think about me MDing in the park. I have asked both local and county officers and they mostly say they would not give me a second look. But I guess it really depends on who sees you and how strict the town is about enforcing the code.