The Sioux sites at Raccoon are open year round. No electricity but there is a water pump and the pit toilets are clean and well (solar) lit 24 hrs. Four sites, each offers some privacy though we had the place to ourselves in early March.
The nearby hiking is great. Try the Wetlands trail for a glimpse of beavers.
From the park office head away from the main lake and campground for about a mile then follow the sign to Sioux up the hill.
Site 5 is a pull-through but closest to the 2 group tent areas and toilets. site 4 a bit damp, 2 and 3 nice.