the flag
http://www.50states.com/flag/caflag.htm

the music
http://library.ca.gov/california/cahinsig.html#Heading15

State Rock California has a greater number of minerals and a wider variety of rock types than does any other state. Serpentine, a shiny,
green and blue rock found throughout California, was named the official State Rock in 1965. It contains the state's principal deposits of
chromite, magnesite, and cinnabar.

skateboard
http://liquorworld.com/skate.html 
Skateboarding  is important in California, there are many shops for skaters.
Skating  is like a religion !