Commercial airlines serve only 27 of California's public-use airports.  The remaining 214 airports are considered General Aviation airports.  The term "General Aviation" most commonly refers to all aviation activity that is neither military nor scheduled airline.

Take a look at "General Aviation Airports:  A National Asset"

In cooperation with the greater aviation community, the FAA conducted this groundbreaking 18-month review of these 2,952 landing facilities (for the purpose of this report, these landing facilities including mostly airports, but also some heliports and seaplane bases, are grouped together as general aviation airports).

California's General Aviation Airports:  Links to Vitality
Connecting communities to the world, airports are economic magnets providing revenue, services and opportunities. Airports boost quality of life and, in disasters, may be the only means of transporting people and goods. Still, the threat of airport operations reductions and closures is real. Without consideration of long-term effects of zoning and permitting decisions, airports are being surrounded by incompatible land uses. This video shows what several California communities are doing to improve land use planning around airports so their airports remain sustainable.

The National Plan of Integrated Airport Systems (NPIAS) report for Fiscal Years (FY) 2017 to 2021 includes approximately 158 of California's public-use airports.  This does not mean the the remaining some 58 public-use airports excluded had no value to the public.  There are many possible reasons they did not qualify, such as they did not meet the minimum entry criteria or were located within 20 miles of another NPIAS airport.  Inclusion in the NPIAS remains a requirement to receive federal funding from the Federal Aviation Administration.

Below are the locations of the NPIAS airports in California: