I have camped here twice now, once during a scouting trip in 2016 with my boys and again in September 2024 with just me and my dog :).  I could pull my 17' pop-up "A" frame trailer and back into one of the two spots with no problem.  Due to the narrow road, it may be a bit more snug with bigger rigs (25+ feet long and anything more than 8+ feet wide).  I would scout the road and area before committing; however, there is a turnaround that you could use to maneuver the trailer to drive out.  It's plenty big to accommodate a few trucks/cars and one, maybe two towable trailers.  If you're going tent camping, there are about four flat places for tents.  The area has no trails, so you would not have to worry about people wandering into the campsite. The Ape Caves is a small drive away. The town of Cougar, WA. is about 10 miles away if you need gas or food.  There is a lot of shade, and it is not solar-friendly.  The main road is about 100 feet away, relatively quiet, and very private.  There was a large rock fire pit in the middle. There is no cell phone reception; however, if you drive East for a few miles, you may be able to get 2 bars with Verizon.

Per the state website, "On the southwest side of Mount St. Helens, Forest Road 81 provides an experience away from crowds. On this road, access Kalama Horse Camp, Red Rock Pass, and Forest Road 830, the road to Climber's Bivouac, and the start of the summer climbing route. From the west, the road begins on Forest Road 90, near Cougar, WA, and travels through private timberlands and state lands before entering Mount St. Helens National Volcanic Monument. The road connects with Forest Road 83 on its east side. While mostly paved, be prepared for several miles of gravel(between Forest Road 830 and 8123) and a road that is sometimes very rough."