We arrived at Diamond Lake Campground (a Forest Service campground) on Oct 5th. They had closed half of the campground 'for the season.' We keep wondering when the government will keep campgrounds open longer in light of the changing weather that's come with climate change.
Anyway, they don't accept reservations, and the remaining part of the campground was pretty full, so we drove through the loop a couple times looking for the best available site.