The California Fuel Cell Partnership (CaFCP) says the states needs 68 stations by 2016 to support what it calls "the early commercial market" for FCEVs. Most of these stations, which would cost about $1 million a pop to build, would naturally be clustered western Los Angeles County, Orange County and the San Francisco Bay Area. The expansion would support the estimated 20,000 FCEVs that may be on California's roads by 2016, and there could be over 50,000 by 2017. The CaFCP says there were eight publicly accessible stations as of the end of last year, with 14 more under development. While those numbers don't sound extremely radical, consider that just 27 hydrogen refueling stations were added worldwide list year.
So, grab a cup of coffee and check out the CaFCP's 28-page report here in PDF.