What is it about Marin? (Wait, don't tell me....)

I did a similar ride last year, the Tour of Marin, with Dave Zabriskie, Levi Leipheimer, the women's US Pro champ and the delicious Fast Freddy. SO much fun. Man those guys are fast - and I caught Tom Weizel (is that his name) the owner of the Postal team going down the backside of White's Hill at about 40 - that dude is one chubby FAST descender.