Seligman/Route 66 KOA has the cleanest and nicest bathrooms. Quite impressive. The owner has done a lot of work here.
The campground has all pull thru sites which was very nice after a long day on the road. The campground was pretty quiet, although they do have railroad tracks within a 1/2 mile of the campground they did not blow their whistles so not really a bother. The free wifi was pretty fast and a strong signal. The pool was lovely with a nice deck and nice pool furniture.
They also have a dog park, several camping cabins, horseshoes, a laundry facility, and a playground.
The only other thing is the people working there were very nice and helped me with a problem I had with my fiver. Even letting me use personal tools.