Here is a rough idea of the course profile for the 2008 run.  Note that the distance is just over 29 miles according to this map.  Based on my measurements, the course is closer to 30.5.  It will be just shy of 31 miles probably, but will have over 5,000 feet of ascent and descent over those 30 miles.  That should give you a decent workout.  Check it out: