You can start at Boxley, AR at the intersection of highways 21 and 43, then go east on 43 towards Ponca (this is the Boxley valley). Then go past Ponca about 5 miles and turn north (left) on Hwy-103. Your final destination will be at the intersection of Highways 103 and 412 in Osage, AR.
After turning on Hwy-103, Kenner Creek creates a 15 mile-long valley, and the road/scenery rivals that of Boxley valley. Plenty of curves with beautiful scenery, plus a good road. I know the Boxley run is already listed on the map of great roads, but it's that stretch with the additional 15-20 miles from Ponca to Osage that makes this one, long gorgeous ride.
Road quality is good. The curves are a mixture of sweepers and twisties, but the twisties aren't extremely tight. The scenery is first-rate.
About the only roadside amenity is the town of Ponca, where there are cabins and basic food supplies. The nearest larger town is Jasper, about 15 miles from Ponca (take Hwy-74 east)