New Mexico offers an annual pass to all their state parks. Out-of-staters can get it for $225. Campsites are usually $10 a night, so the pass is worth it if you plan on spending more than a couple of weeks a year camping in the state. I do.
Right now I'm at Elephant Butte Lake, next to Truth or Consequences. I don't know yet which hill is Elephant Butte, but I know exactly where the lake is.
My primitive campsite (unpaved, no covered picnic table, no toilet, no electrical or water hook-ups, etc.) is on the top of a hill with 360 degree vistas. I like it better than the RV sites, if for no other reason than I don't have neighbors. Just me and some critter tracks.
Well, it's not totally primitive.