Nothing too serious - about 3,000' or so of climbing all told. Basically, the 100 mile ride is a big quasi-figure eight (assuming they use the same course).
You start at Bonfante Gardens, ride across the valley, and climb up to the hot spirings. Then you backtrack some, turn and climb some more, and then descend and loop back to the valley floor. You cross over the valley, turn north and go that way for a good while , stopping at the Pearl Izumi outlet and then ending up at the Specialized offices. Then it's more flat ground, up into the hills, loop around and back to Specialized. Then you go back south to the beginning.
Too much crossing back and forth/looping around for my tastes, and last year the course was poorly marked with tiny little arrows that were right on top of where you needed to turn. A lot of folks went astray.
But then again, it is probably the last organized ride left this year hereabouts, save maybe Solvang.
Here's a link to last year's discussion:
http://www.bikeforums.net/showthread...light=bonfante