Not in Comanche Park but real close. Very remote pretty level sites you can get. Some area have WiFi others not. Custer town is close by also Crazy Horse, Mt Rushmore, and plenty of lakes..
Stayed here one night on my way to Mt. Rushmore. The actual campground is open late Oct-April I think. But there are 5-6 sites outside the access gate to use when it’s not open. Has a pit toilet that was clean. Easy place to stop for the night.