We stayed 4 nites in loop B first week of September, 2017. Very quiet. Some sites small, but we were ok with our 25' MH. No dump, no water fill. Great staff and naturalists.
National park with power available on loop B, mixture of pull through and back ins. Good privacy between sites, you need to take your own water and no dump station. Pit toilets.Was $22 with power.
We stayed in the south rim campground at Black Canyon NP. Loop B has electric. There is water but it is trucked in so it is limited. The facilities were clean. We stayed in site B12. Sites are separated nicely from others. Site B13 power didn't work so check your power before unhooking your trailer. We will stay again.