They've got at least a dozen of these with even more elevation gain throughout the season in California (plus a few more with less than 10,000' of climbing). Finish any three and you have accomplished a California Triple Crown, and you are entitled to wear a nice Cali bear flag jersey (looks a lot like their state championship jersey, in fact). I did my first Cali TC this season: Davis (8,000'), Borrego Springs (15,600'), and Knoxville (12-15,000' depending on who measured it). But I thought I'd make it more of a challenge and did all three on the fixed gear. So they're not that difficult, as long as you're resigned to starting and finishing in the dark.
But the support for these rides has been uniformly excellent. In fact, for Knoxville, held at the end of September, temps got up to the 90's F and they had extra water stations put in. At the end we had two different kinds of pasta (in alfredo & marinara sauce) and grilled chicken breast, and all sorts of sodas and juices to drink.
I think the Californians have got the double century pretty well down pat.
Luis