There are two camping areas in Curtis Canyon. The actual campground and the dispersed area. The dispersed area is beyond the developed campground. The sites are scattered along about 9 miles of beat up mountain "road". It's really more suited for OHVs than cars. The road is absolutely terrible. Sure, you might be able to make it up in a sedan (we saw people do it), but you also might tear some parts off (we heard a good bit of that as cars passed our site). We pulled a trailer up this road, and while we made it up and back with no mishaps, is was slow. Sloooooow. And very rough. The dispersed sites have no water nearby, so you'll have to find a stream or drive up to 9 miles back to the developed campground to get water. I would not recommend this road to anyone with a low clearance vehicle or a trailer over about 18 ft or a motor home. It is a terrible road and once you start you are committed to it because there are no places to turn around until you reach the developed campground.
This area is also very crowded. If you arrive much after 2pm you will have some trouble finding a site. We arrived at 3 on a Tuesday and passed a lot of occupied sites before finding one available. We saw a lot of other people arrive after us that could not find sites. The sites are not very level, but the views are incredible.
I would camp here again, but I'd leave the trailer and the big tent and just come with a 2 person tent.