In a state park you would have to carry your gun unloaded and encased. However Kettlemoraine in general is a state forest therefore it's not subject to the above ruling, yet the kettle moraine state forests may still have some other specific state forest rules that I'm unlear of. Devil's lake IS a state park though and it would confine you to carrying encased and unloaded.
What do you mean SOuthern Kettle Moraine state "Park? Kettle Moraine is a State forest.... not a state park theres a big difference when talking about firearms in regards to parks or forests. So you should be fine open carrying there, unless they have forest specific rules "deemed' by the state. I hunt southern kettlemoraine too! mainly coyotes and rabbits. Maybe I'll have to indulge in some coyote hunting with my WASR one of these coming up weekends at the southern kettle moraine.
Try to remember for future reference the statute I stated above is for state parks, those are the general blanket regulations when it comes to the parks. The state forests have no real general firearm rules specific to them. Unless it is posted in the hunting regs or inthe state forest. i.e much of the north side of zz in the kettle moraine southern unit is closed to firearms I believe, not totally sure though. But if a state forest does have regulations regarding firearms they are usually put on signs in the parking areas or along the road.