I just heard from the mission home and here it is:
Elder James Caleb Clark
California Anaheim Mission
2500 N. Bristol St.
Santa Ana, CA
I was told the zone leaders come into the mission office twice a week to pick up packages and deliver them.
If you are sending perishable items, please write on the package: Perishable or Deliver ASAP or Baked Goods and they will make a special delivery to get those packages on that day it arrived.
Please write him often.