Here is a direct link to the statewide unemployment data, with several graphs.
California’s basic dilemma is that the state’s population has grown since Jan 2001, but not the number of jobs.
Specifically, the number of people in the state has increased by about 4.5 million, while the number of employed people is almost exactly the same at around 16.2 million, down from a peak of 17.1 million.
Some of the population growth was children and retirees, though California has a low birth rate and is an expensive destination for retirement.
Therefore most of this population increase consists of adults who do not have jobs, whether they are included in the official U3 rate of 11.9% or the depression-level U6 rate of about 19.9% that includes “discouraged workers” who want a job but have given up looking, and those working part-time but looking for full time work. (The 19.9% rate is an estimate based on adding the Q2 2009 U3/U6 gap of 8 points to the current U3 rate).
Looking at the major counties, Marin has the lowest U3 unemployment at 8.2%, while Riverside and Fresno have the highest, at 14.9 and 15%.