Cal. Prob. Code § 3921
Subject to the power of the court to transfer actions and proceedings as provided in the Code of Civil Procedure, a petition filed under this part shall be heard and proceedings thereon held in the superior court in the proper county, which shall be determined as follows:
(a) If the minor resides in this state, in either of the following counties:
(b) If the minor does not reside within this state, in any of the following counties: