The Middle Creek Trailhead into Big South Fork is a few miles north of Tanglewood, in the same vicinity as Pogue Creek and Pickett Parks. Head out 297 to 154 North. Just before Pickett Park there’s a gravel road to the east off 154. Take that to the Middle Creek (and other) trailheads. There’s a big sign there so you won’t miss the parking area along the gravel road.
Here’s a trail map of the 3.5 mile nature loop. There are many trails out of this area, so explore the link above or just follow the wooden signs!