CA Gun laws re open vs concealed carry:

http://www.californiaopencarry.org/faq.html

What is Open Carry?
Open Carry (OC) refers to the act of carrying a firearm in plain sight.

Is Open Carry Legal in California?
Open carry of loaded firearms has been illegal in California since Governor Reagan banned it back in 1968. With the recent passage and signing of AB 144 by Govenor Brown, Open Carry of unloaded handguns is no longer legal in most of California effective Jan 1, 2012. As such, most of this FAQ was obsolete and has been deleted.
Is it true that carrying both a gun and ammo is legally considered loaded?
No. If one carries a firearm with the intent to commit a felony, then it is true. But for the typical law-abiding gun-owner, it is not true. PC 12031 and People v. Clark are all that apply. For more information on the topic, read Defining Loaded in California.

Where can I legally Open Carry?
Loaded Open Carry is legal in your home, temporary residence or campsite (unless otherwise prohibited), place of business, private property, and in areas of unicorporated territiry where shooting is not prohibited, including most areas within National Forest and BLM lands.
With AB 144 becoming law, Unloaded Open Carry of handguns is now illegal except where loaded open carry is legal, and also in public lands (National Forests, BLM, etc.) where firearms are permitted.

Unloaded Open Carry is still legal for long guns (rifles and shotguns) anywhere except the following places:

schools and "school zones" (within 1000 feet of a K-12 school)
California State Parks
"federal facilities" within the National Parks (details)
US Post Offices and other federal buildings
any state or local public building or at any legislative meeting required to be open to the public
the State Capitol, legislative offices, office of the Governor, Governor’s residence, etc.
“sterile areas” (areas where access is controlled by security screening) of airports
areas restricted by local city or county ordinance, often including regional parks

What about rifles and shotguns?
PC 12025, which makes carrying a concealed handgun illegal, does not apply to long guns so they can be carried concealed (in a vehicle, for example) or unconcealed. However all other laws apply (including PC 12031 which makes carrying loaded illegal under most circumstances).
Update: The new Unloaded Open Carry ban (AB 144) does not apply to rilfes and shotguns.

My question isn't answered in this FAQ or in any of the documents on this site.
Go to OpenCarry.org's California Forum and ask. To contact CaliforniaOpenCarry.org's site administrator email admin at california open carry dot org. (CaliforniaOpenCarry.org is not affiliated with OpenCarry.org.)
Legal Disclaimer
The information on this site is not legal advice. This site contains information about the law. The purpose of presenting this information is to help the law abiding gun owner exercise his or her rights, while still remaining within the law. The authors have gone to great lengths to assure that the information is accurate and complete. However, legal information is not same as legal advice, which is the application of law to an individual's specific circumstances. Consult an attorney for legal advice.