The campground we found, courtesy of Wisconsin State Park rangers, was Calumet County Park. It is a fairly small campground, situated on the eastern side of Lake Winnebago. Like the state parks, it is also very popular, and we could only book a camp site with electricity until Friday, as the electric sites were already booked for the whole weekend. We decided to camp for 3 days, and head up north early. The campground has about 50(?) or so sites, some right on the lake, but most just off the lake. They also have a camp store, laundry mat, and bathing beach, sort of.
What we saw of the beach was not overly inviting. Near one picnic area is a public entrance to the lake. The lake here is a little rocky, and the swimming area didn't seem very large - and we were the only ones swimming at the time. For some reason, campers or swimmers feel the need to drag picnic tables into the water at this spot, which also deteriorated our view of the swimming hole. If you are accustomed to sandy, wide beaches, Calumet County Park is not your first choice. But, it was clean and nice and overall, a very pleasant place to camp. Most of the sites we saw were huge, especially when compared to those in Michigan State Parks. An added benefit was a nearby bar/restaurant. The food there was good, plus the owner filled us in on what we had missed of "Survivor" the night before. Our memories of the area are very pleasant, even considering huge lightning/rain storms our first two nights there. We got so much rain, one camping neighbor joked about seeing an ark. The grounds handled it well, though, and standing water was not the problem it could have been, considering the downpours we got.
Lake Winnebago is quite a large lake, and may be one of the few with lighthouses on it. There are three listed on the lake, but at least one is privately owned. The lighthouse at Fon du Lac is part of a public park, and is open to walk up. We had a pleasant lunch at a nearby A&W, then toured the lighthouse area for a half hour, before continuing our drive around the lake. If my memory serves me, it is about 8 miles long, and 3 or 4 miles wide at some spots. We spent a lazy day exploring a little, and generally taking it easy. Our time at the campground was most restful and enjoyable. We did take a day to tour the Wisconsin Dells, and parts of Door County, but those are stories to come.