I literally had the entire state park to myself yesterday, Tuesday, in the middle of summer. I was hiking and there were no other cars there. The night before it was me and one other camper in 10 sites. We have 10 walk in tent sites. You need a reservation. It's $15 a night for up to six people per campsite. There's a picnic table in a fire at each site. There are pit toilets. There is no electricity anywhere in the park including no lights even in the parking lot. It's awesome. Great to see the night sky.
On the east side of the park there is a picnic pavilion and several picnic tables with a charcoal grill On rainbow lake. Straight Lake has a boat access so does rainbow lake, but you have to carry the boat from the parking lot. Non-motorized boats only Like canoes and kayaks.
Several miles of singletrack hiking trails as well as the Ice Age national scenic Trail which transects the park.
I had trouble finding firewood in the area so I could not have a campfire. You're supposed to bring it in from only 10 miles away and the gas station in Frederick and Luck did not have any and I didn't see any roadside stand selling wood.
If you want tranquility this is your place read more