"Whypass Trail" is a bit of a misnomer as this is actually a system of interconnected trails that run through the forested hills on both sides of the paved BLM road the parking lot is on. Although this web of singletrack can seem a bit confusing, there is little chance of actually getting lost since virtually every rideable section of it eventually leads back to the road.
The trails here vary from narrow and unimproved to fairly wide, much improved singletrack designed specifically for MTBing. The latter of these are excellent in quality and include features such as large, well-constructed berms and jumps-things you won't find on the Forest Service trails in this area. They also differ from those trails in that they don't go anywhere. That is, there are no rivers, lakes, connectors, hinterland shelters, alpine meadows or sweeping vistas to be had. The trail is what it is: a MTB trail. But it is an excellent one.
Nowhere are the trails excessively rocky or rooty, and the majority of them are exceptionally smooth, winding and fast. There are a number of switchbacks and several fairly steep, but mostly short, climbs. Anyone riding here can expect to enjoy hours of exploration, or hours of finding and riding favorite (and exhilarating) loops. The variations are seemingly endless.
There is very little signage on the system, and no official map that depicts it in its entirety, so come prepared to explore. Also, there are no perennial water sources, so bring as much as you'll need.