Paul, it sounds like your group will be right where we are camping. I'd say about rock throwing distance, give or take. Your description matches our site exactly.
I live about 130 miles from T-haven. One or two other people attending live maybe 30 miles closer, but sure, you can drop and change tires at my house. Although I strongly urge you to reconsider not bringing your Thornbirds, what a hassle when you can use mine. Plus I think my BFG's will out perform yours in this terrain.
Char, maybe an axe isn't enough, what do you recommend?