There are a lot of beautiful campsites on the  Modoc and  Fremont national forests

Evening fire Lassen Creek, 2004. , by Geoffrey Rutledge
Some favorites are Lassen Creek Campground (which is slated for closure. Please write and ask for it to stay open) which is a very convenient and pleasant place to stay when flying the more southerly sites.  Davis Creek Mercantile is the nearest food and gas.They also serve great breakfasts.
   Cave Lake is another favorite, a little more remote not so close to flying sites.
 Stowe Resevoir is another beautiful remote campsite that is halfway between Alturas and Cedarville good if flying Surprise Valley.
Camp Fire Lassen Creek, 2004. , by Geoffrey Rutledge

 For folks looking for more amenities the Goose Lake State Recreation Area at New Pine Creek has electrical and water hookups, hot showers, flush toilets, dump station etc. etc.. It is possible to go there and just pay for a shower and stay more remotely.

  The Hunters Hot Springs resort in Lakeview has rooms and they sometimes have camping on site. There are numerous motels in Lakeview and in Alturas to the south and one motel in Cedarville