open carry of pistols is against the law in CA and i doubt anybody will believe you are actively target shooting or legally hunting during KOH week. while nobody will probably say anything, if you are even a little paranoid about it, i cannot recommend open carry.
concealed carry is legal with a CA permit and isn't always super rare to get. CA does not honor (any?) out of state permits, but if you are carrying concealed and somebody happens to notice, odds are extremely high that they will simply assume
That it's none of their damn business and they should keep their mouth shut.
If you are concerned about traveling and being pulled over, then you should probably not have it on your person or somewhere that it will be noticed by somebody walking around your vehicle.
I have heard of people carrying concealed without a permit and if you look at CA arrest records, it isn't as uncommon as the man would like you to think. it is a misd. if you are not breaking any other laws at the time.
hell, the $500 fine is damn near the cost of getting the permit