It kinda depends on the size of your rig. There are a number of parks in the Long Beach area and then none really till you get up past Raymond,then there are a couple at Tokeland.One of those is pretty nice and the other is kinda nice,but basically a fishing camp. From there is Grayland SP,then Twin Harbors SP which is for smaller rigs. Lot's of tent camping and a few 30' and less h/u sites. There is one or two in Westport. Hoquiam River is very nice and then you're heading out to Ocean Shores with Ocean City SP which is hard to get into. Up from there are several member campgrounds,which will usually let you stay there and severale of those are Passport America.There is a small grundgy one on Lake Quinalt and then Klaloch NP,no h/us. The one at Forks and one at Lapush are private and Mora is a NP cg with mostly small sites. Thewre is a private CG at Neah Bay and then you're in hog heaven from there into the Puget Sound area. If you're retired military,there is,I believe, a campground at Pacific Beach and on the ocean at Neah Bay.
OOPPSS,I forgot Pacific beach SP,almost impossible to get res there and Bogachiel River SP.
We've stayed at almost all of those over the years,with the exception of Klaloch and Bogachiel.