Thunder Rock Express is either one of the best descents or tougher climbs in the Tanasi trail network. It is usually ridden as a descent from the Chestnut Mountain Loop down to road FS45.
The descent is fast, flows well, and, due to the amount of loose rock on the trail, can be ridden at speed even when wet. Be careful, though, as the trail is narrow and built into a steep mountainside with sharp drops to the side. A turn taken too wide can result in a long tumble.
The trail starts about halfway around the Chestnut Mountain loop and ends on Forest Service Road 45. From there, riders usually take a left onto FS45 and climb to West Fork Trail to reconnect to Chestnut Mountain Loop.
This trail is one of the highlights of the Black Bear Rampage 40 mile race.