If you happen to be coming the northern Wisconsin into the UP route we love Munising Tourist Park Camp Ground | Online campsite rentals in the Upper Peninsula, Michigan
not a ton to do in the park except breathtaking views of Lake Superior (had to bribe the kids with $1 each to go all the way underwater it was so cold!! LOL!). In town you can do a sunken shipwreck/glass bottom ship tour and also the Pictured Rocks boat tour. The PR boat tour is best taken on the sunset cruise...the rocks are spectacular in the evening!
Tahquamenon Falls' Rivermouth state park is a quiet yet beautiful place to start your adventures in that area.
For Mackinac Island I have to respectfully disagree on Mill Creek campground. Yes, its a nice looking
park, but there are rules, rules, rules, and regulations on top of rules. I had a park guard chase me down on a golf cart and yell at me for less than idling through the park as "way too fast". I could not fit my TV on my site and had to park it elsewhere. We were given a small oil change pan for our campfire, and my awning couldn't be fully extended as to not hit the camper next to me. No thank you. I'll take my camper to Castle Rock Mackinac Trail Campground, Castle Rock Mackinaw Trail Camp Park, St. Ignace Michigan Attractions and Lodging
just across the bridge.
If you make it around to Petoskey, we love the beach at Petoskey state park.
Enjoy the trip, we have a great state here and I am positive you will all feel the same way!