Hey, Bouncybouncy, there's an annual mountain bike ride UP Mt. Mitchell. This year it's July 31:
http://www.wncmountaingoatepics.com/...t_mitchell.htm

And Doc, believe it or not, 5 hours in the rain is not as bad as it sounds. Once you're wet, it doesn't really matter anymore (as long as there is no lightning). You just can't draft because of the dirt and water being spewed up into your face. Three of my girlfriends did the Marion ride, and another girlfriend and I did Mitchell. I have to admit, things were a bit 'dodgy' at the start, with that many riders on wet roads, but our group was very lucky, no accidents, no flats. The good thing about the rain was that it never got hot.

Sorry it didn't work out for you, but I hope you'll give it a whirl next year.