The Dry Hill trail network is located on WA DNR land and is maintained by the Olympic Dirt Society. The area is best known for its collection of downhill trails and the NW Cup race series. The trails are open year round, but there is no vehicle access except for on event days WA Discover Pass is required for parking.
The top of White Knuckle is a high speed doubletrack along the edge of the clear cut. It's a staple race trail and is pretty smooth with a few poignant exceptions. If you hit the road crossing fast enough it serves up quite the step up jump.
The bottom half of White Knuckle is a less developed track winding through the woods. A few steep rock slabs keep things interesting. Motoguzzi, or Double Bypass may be more enjoyable options than this bottom section of White Knuckle.