2021 Information.
An excellent campground for tents and small trailers. Big trailers should avoid this due to the road up and the lack of larger flat pads to park on. The NPS website has clear information on trailer size. We noted someone with a larger unit roll in and have a rough time finding a pad that would fit it. They got lucky as it was a Thursday... in busier times they would have been driving back out.
Also... Bring 20 dollars per night for the paybox. Credit only down at the entrance station...miles away down the mountain.
Loop A - Limited first come, first serve sites. Many sites reserved for volunteers or closed due to tree hazards. This is a shame because Loop A to me is the best for tent campers based on site size and site isolation. You may snag one if you get in on a weekday or get really lucky.
Loop B and C - seemed to be mostly open with few tree hazard closings. The loops are also really nice for tents. Sites tended towards a bit more sun than A. Some spots are okay for a small trailer, but it really depends on the camper size.
Loop D - lots more sun on these sites. Less privacy. Might be easier to park a trailer due to flatter leveler pads in general.
Bathhouse Info - Every loop has a pit toilet setup and a bathhouse with running water and flush toilets. Water faucets are at both pit toilets and bathhouses, but you will have to carry water a distance. No showers and no hot water. Also no lights in the restrooms.
The bathhouse with running water has the camp sink for washing dishes and preventing bear issues. You might have to walk dishes quite a distance for cleanup.
Bear County - Don't be stupid and leave food, water, or smelly items out. We saw black bear off the road on multiple occasions during our visit.
Holidays - Expect it to be very busy around holidays.