> > The county shire-reeve is quite helpful in policing the unincorporated areas.
> Indeed that's their primary function in California.
I think that depends on the county and the degree and population of unincorporated land; running the local detention and corrections system is arguably a more important role in much of California (certainly so in SF, where the City and County are coextensive so that there is no unincorporated land to police.)
At the other extreme: in Massachusetts their primary function is to provide a favor for some someone the governor owes a favor.