Cal. Commercial Code § 9301

Except as otherwise provided in Sections 9303 to 9306.2, inclusive, the following rules determine the law governing perfection, the effect of perfection or nonperfection, and the priority of a security interest in collateral: (1) Except as otherwise provided in this section, while a debtor is located in a jurisdiction, the local law of that jurisdiction governs perfection, the effect of perfection or nonperfection, and the priority of a security interest in collateral. (2) While collateral is located in a jurisdiction, the local law of that jurisdiction governs perfection, the effect of perfection or nonperfection, and the priority of a possessory security interest in that collateral. (3) Except as otherwise provided in paragraph (4), while negotiable tangible documents, goods, instruments, or tangible money is located in a jurisdiction, the local law of that jurisdiction governs all of the following: (A) Perfection of a security interest in the goods by filing a fixture filing. (B) Perfection of a security interest in timber to be cut. (C) The effect of perfection or nonperfection and the priority of a nonpossessory security interest in the collateral. (4) The local law of the jurisdiction in which the wellhead or minehead is located governs perfection, the effect of perfection or nonperfection, and the priority of a security interest in as-extracted collateral.