Quote from aikigreg on May 16^th, 2010, 10:46pm:

 
Looking at the altitude and climbing I'm of the opinion you want to kill us

I'd encourage everyone to do this ride.  The first time I did it on my upright, but I've never finished it on a recumbent (I get to about 50 miles and crater) but you stronger riders will have no problem.  Great scenery, usually (but not always) nice and cool.  One heck of a downhill coming down from the observatory, but be mindful of the speed warning sign on one turn.  You don't want to go over the top of the wall!
Caution:  there is NOTHING along the 75 mile loop.  No stores, gas stations, really not hardly even any houses that are accessible.  Any water or food you'll need you need to take with you.  There are no short cuts, bail outs, etc., and cell phones don't work.
Profile of ride (bottom display) can be found here:  http://www.peytonsbikes.com/ftdaviscyclefest.htm
If I remember right, it's 5280' of climbing (and descending of course!).  And it is my all time favorite ride, though I've only done the supported one in September.