Stayed for about 4 nights and saw a lot of people come and go- it’s fairly busy. There seems to be a more long term camping spot set up closer to the start of the road that had a bunch of big trailers and port-a-potty’s set up. Not sure if they work at the quarry or something else? If you go past them there’s some spots along the road to pull into that I saw a few short-term campers use, and then even more once you reach the base of the ‘quarry’ area. It seems to be active (excavators are lingering around, though I never saw them in use). I would just say make sure you find a spot that’s not blocking the road, there’s some random roads that go in around the base that I think the excavators use part of, but there’s camping spots among them and lots of places to back cars/ trailers into. (look at satellite images to know what I mean).
The road to the top is fairly steep/ rough at the first section but then seems easy but bumpy onwards. I saw a non-four wheel drive car make it up by gunning it at that steep part. I attached a pic of what that first steep part looks like.
If you do make it to the top, there’s great views and cell service. Just get in before 4pm and it’s probably yours.
And of course crater lake is a 40 minute drive away, which was the main draw for me!