Section 4763 Of Chapter 2. Jurisdiction And Venue From California Probate Code >> Division 4.7. >> Part 3. >> Chapter 2.

. The proper county for commencement of a proceeding under this division shall be determined in the following order of priority:
  (a) The county in which the patient resides.
  (b) The county in which the agent or surrogate resides.
  (c) Any other county that is in the patient's best interest.