Cal. Rev. & Tax. Code § 14002

In the case of a decedent who was not a resident of this state at the time of his or her death, the superior court of the county in which the decedent’s real property is situated, or, if he or she had no real property in this state, the superior court of the county in which any of his or her personal property is situated, has jurisdiction to hear and determine all questions relative to any tax imposed by this part. If the decedent leaves property in more than one county, the superior court of any such county whose jurisdiction is first invoked has exclusive jurisdiction.