I was up there fishing a few weeks ago and noticed some nice looking campgrounds right along hat creek off hwy 89, on the was towards Mt. Lassen. I hear that section of the creek is heavily stocked with rainbows, and even has some huge resident browns. Id get up there as soon as possible before this hot weather slows the trout bite. For more info about the hat creek area check out www.flyfishnorcal.net for the most recent reports.