Chris Brandt
Specialized Armadillo tires are perfect for this event.
They have a new version this year that uses kevlar bead instead of the previous ones that used wire. So, now they are only about 40 grams heavier than the standard tire. I've been riding the gravel w/ them (25's) and they are tough. They are called Roubaix for a reason. I've not flatted w/ a pair of the wire beads after three seasons of winter rain miles. I only replaced one when I got a nasty cut from a huge nail, but it still didn't flat. Nice thing is that you don't have to mess around w/ a kevlar tire liner like someone mentioned. With a larger volume one, like the 25, you can get away w/ running lower pressure too.
I've also ridden the gravel Cantrell road many times in the past and not flatted using regular race tires. I have noticed though that the rubber on those tires gets cut up a bit more. At those particular times, the gravel was in much worse shape than it is now. Sometimes it can get really washboarded and w/ larger chunks of sharp rock. No worries now, plus after the Dukhobar section (which I was really looking forward to - Arrrrg!) got removed from the course, the gravel is pretty much a non-factor.
Chris