One of my favorite camping spots in Utah or Arizona is Kodachrome Basin State Park almost to the border of Arizona deep in the sandstone cliffs of Southern Utah. It is a relatively small area with lot of interesting formations. Unlike some of the more popular national parks, Kodachrome is not nearly as busy or crowded. It is not particularly on the road to anywhere so there is less traffic than some other areas of Southern Utah. If you are thinking of camping, you will need reservations.