this is the response I got:
"The mountain bike scramble is an intermediate ride. I have not ridden any of the trails you mention so I don't have a reference point. I believe trails are what you make of them. I take my time, sometimes push my bike up hills or over rocks. It's not a race so take your time, rest when you need to, replenish fluids often, and you'll do fine. Please bring a new tube for your size tire. There will be people to help with repairs if you need it, but tubes vary in size and SAG vehicles will only be available for the road cyclists. See you there!"
So, I think I might try it. I've still got two more days to chicken out. One person's "intermediate" might be my "advanced".
Mapquest said it was an hour and half drive!!!
There are ATV trails too, and DH was kinda keen on that; he's got a seat on his ATV for Andy.
I'm pretty sure I won't get in a ride today (unless I ride on the road), the river doesn't crest till tonight, and I'll bet it's muddy with trees down.