Ernie,

i understand your love of copper and that the POT utility is usually the last man standing after some sort of disaster, but in your earthquake prone area, if the copper is broken, it doesn't matter how stable the central office might be. Also, be careful to keep a really old handset around because the newer junk probably needs batteries or a charger. (you could use a solar charger)

On the plus side for the cell network, a heard of COW's could be brought in to temporarily support an area that was disrupted, but there is a finite number of COW's available for redeployment. Of course, this assumes that the users have some means of keeping their phones charged.