You shouldn't have any problem with this knife if you open carry it. California doesn't distinguish between lengths of fixed blade knives: all fixed blades are legal to carry, but illegal to conceal; the relevant section of state law is "Concealed Knives, Dirks, and Daggers – CA Penal Code § 12020." You can't brandish it, or bring it inside schools or on college campuses (2.5"+).
I've had zero issues carrying my Bradford Guardian 3 attached to my pack while hiking and camping. Disclaimer: I'm not a lawyer, and local laws can vary - LA has laws against 3"+ blades, for example. Also, being on the right side of the law doesn't prevent you from being questioned, detained, or even arrested. Carry wisely.