If you're looking for something more challenging than Tahuya there is . . . a parking lot.
Seriously, though, Walker Valley ORV park or Reiter Trails are a lot of fun, more challenging, and still below the snow line.
Elbe. . . can get challenging. Be prepared for body damage if you go down there. There are some easy trails and then there are some difficult ones that can get nasty.
For Walker Valley poke around on the WA State DNR website and they have an ORV map of the area and I think some directions on how to get there.
As for Reiter I'm working on a trail map of that area. You're more than welcome to download and print the low-res map image I currently have.
Black Routes = Pavement
Blue Routes = Gravel Roads
Green Routes = 4x4 trails
As for getting to Reiter. . . Head east on Hwy 2 out of Monroe. Go to the town of Gold Bar. On the eastern outskirts of town turn LEFT onto Reiter Rd. Stay on Reiter Rd and when the main route makes a sharp left turn bear "right" which is essentially going straight ahead. You'll come out of some trees, a quarry will be on your right, the main parking / staging area will be on your left. Explore. Total distance between Hwy 2 and the staging area is maybe 1 mile. . maybe 1.5 miles.
If you miss the Reiter Rd turn off and cross a bridge on Hwy 2 you've gone too far. . .the bridge is about 1 mile or less past Reiter Rd.
Aw heck. . .