We came to Craters of the Moon early, ended up being there most of the day. Instead of going on and trying to find dispersed camping, we treated ourselves to a site in the park. Sites are $15, and you must have the American the Beautiful Pass or pay park entry fee. The sites are dry camping with toilet facilities and water (no dump station). The sites are right in amongst lava field and is quite unique.
Campground was very quiet at night and very dark. Could see the sky and stars wonderfully. Definitely a great park and place to stay.