The title of this page should tell you how I feel about this. I hate Wilderness areas because it's absolutely useless. Nobody gets to see these areas unless you're willing to hike long distances, which often means camping out too, with minimal supplies. This doesn't work well for a lot of people, myself included. Heck, many of us simply cannot hike/walk those distances due to back or leg problems.
Okay, enough of the rant. Below are links to the maps of the area. This way you can see where you can ride and where you can't, for the most part. I strongly suggest storing these maps in a PDA such as an iPAQ, for easy reference while you're out there. Note: The super big map, linked at the bottom, won't load up in most PDAs, but the others, which are the big map broken up into pieces, work just fine.
I found the graphic and the maps at the Friends of Black Rock/High Rock website. I don't know where these people stand with regard to OHV access. I wanted to re-post them here because it took a lot of Google searching to find the maps, and I would like them to be more readily accessible.
Overview Map Graphic