I had a talk with my mom. She currently works dealing out building permits for the city of Grand Rapids. I asked her about 2 specific piece of land.
Ah-Nab-Awen Park in a city park right next to the Gerald R Ford Museum. She told me that even though its a city park, the entire grounds of the museum and the park itself is all Federal Property.
I then asked about the public school the sits within John Ball Park, Zoo school. I found out that the building is property of Grand Rapids, but the property outside of it is owned by the City of Walker. Open carry should be no problem regardless. BUT those people that want to conceal carry within the park should take note. I would open carry the closer you get to the school. She wasn't too sure of the boundary between the school and . . lets say. . the band shell. She did direct me to check out Access Kent website to find out more.
