Note that there is no beach. The best little camp store I've ever seen (ice cream to wood to equipment). Close to Sturgeon Bay, so you can run into town for supplies.
2 camping areas, Homestead and Wisconsin Ridge.
Homestead provides secluded, wooded sites with a good distance between them.
Ridge sites have the veiw from high over the Wisconsin River. That view will cost you though: the sites are are very close to each other with little vegatative separation.
There are many burial mounds in the park, and there is an astronomical observatory on site. The only water access that we found was a boat landing on the Mississippi side. High water prevented us from exploring it much.