Developed campground just north of Cedar Cliffs in Virginia (mile #844 approximately)

I came across a campground area with picnic tables somewhere north of the Cedar Cliffs area in Virginia a few years ago. I I forgot the name of the spot. It was north of the Wintergreen area, maybe around Dripping Rocks? The Google map shows a looped roadway section near the Greenstone Overlook but there is no indication it is a campground. The Appalachian Trail had one of those stone columns with a crimped metal band indicating the side trail to this campground but alas no data is retrievable in my cyber searches so far.

I think you are referring to the Humpback Rocks PICNIC Area at BRP MP 8.5. It looks very much like a campground, but it isn't. However, you can stealth camp along the trail that connects this picnic area to the AT. The further from the picnic area, the less stealthy you need to be.

This picnic area is open from late Spring to early Fall and includes restrooms and potable water.