I can't comment on CA, though I still want to live there for 6 months or so just for the biking. But if in late March, consider Fredericksburg, TX and Texas Hell Week............
http://www.hellweek.com/
If you are confident cycling and being on your own, just go to....
http://www.cycletexas.com/..print and plan your own routes. There are some routes where you need to bring your climbing legs. Think about where Lance learned to climb hills. But 1000' per 1s miles or so if easy to find.
If the weather and rain is right, the Hill County will be beautiful.
There is also a ride at LBJ ranch, if you want an organized ride or to enjoy the short history tour led by Lucy Baines Johnson, LBJ's daughter (regardless of your political leaning).
http://www.lbj100bicycletour.org/
As LBJ said....
"all the world is welcome here."
We'll be there the week of March19th on our orange Burley Tandem. Maybe we'll see you.