Trout fishing paradise, really nice & natural for the rest of us. Take Hwy. 76 about 12 miles west of Clayton and go right on Persimmon Valley Road (look for Firestation, if you cross the Tallulah River, you went too far). Go until you see the Brown National Forest sign on the left. Take this road to any one of three progressively more primitive campgrounds... the first is on paved road, and there are more than a few motorhomes, the second two require 3-5 miles of gravel road that is easily traversable by any bike. Stop along the river to fish or swim.
Dillard Georgia. Just north of Clayton on 441, good sites with full services and lots of tents-only places. There is a great spot to take pictures of the sunset over the Appalachians.
N34 29.930 W83 29.217 will get you to the gate. There are two campgrounds, both alongside the 100-acre lake with many excellent tenting spots. My visit was during the winter months, so the better of the two campgrounds (closer to the main section of the lake) was closed for the season. The other site was toward the lake’s north shore. It’s a decent remote spot with reasonable facilities that include hot showers. The lakeside spot looked better but could possibly get more crowded. There are a number of dirt roads in the vicinity and a large wildlife preserve adjoining the lake. And as noted, there is a ton of excellent riding immediately to the north.