Close to Munising and Pictured Rocks.
This is the Otter Lake campground near Munising MI. We only stayed one night. They do have laundry available with the noisiest dryer I have ever heard :). They buildings could use a bit up keep, they have kayak rentals, and nice play area for kids. The sites do not have grass so it is a bit messy- may be tough for larger units to navigate around. Campground is small and the people are nice.
I grew up in Otter lake spent lot's of summers running around the campground and beach area. I haven't stayed in the campground for years but I have visited friends staying in the campground. The campground is right in town and there are a few stores you can walk to. There is a boat launch, park and a beach. This is a modern campground and has updated bathrooms with showers. Water and dump station. Sites have electrical hook ups. The beach area is nice and sandy, lots of places to fish.