Down Yonder Campground is right outside Dale Hollow Lake State Resort Park, Ky. A bit of a drive through Kentucky or Tennessee farmland, closest big city is Nashville to the west.
The owner said that they have been open three years and their websites shows pictures of the rental cabin at the front of the property. Currently they have annual sites only , no shade on gravel. They are in the process of creating overnight sites that will be available by Labor Day 2017. No wifi, steep entry from road and no facilities, to me $40 a night sounded a little high.
Consideing how many big rigs and trucks I saw at Dale Hollow it will probably be busy during peak seasons.