Looks to be a citizen-soldier group authorized by CA to assist the CA National Guard.
http://www.calguard.ca.gov/casmr/Pages/default.aspx
It looks like the “California Military Reserve” is just the way that California refers to its own National Guard & Air National Guard, combined. Not having lived in California, this is just a guess based on looking at their website.
Take that back... it’s definitely some sort of auxiliary organization. Found the mission statement.
General Kerr is a “California General” the way Colonel Sanders was a “Kentucky Colonel”.