There's lots of cool routes in that area - Apex, Mammoth, etc. and Kingston Peak (now impassable by snow, but a real treat. Makes a fun night run, lots of stars, you can see satellites and meteors from time to time due to the darkness and altitude). Not hard 4-wheeling by any means, but scenic in the extreme.
Pick up Charles Wells' books (www.funtreks.com
) for a great overview of the area.