To file and perfect a security interest, you basically always file centrally in the state where the debtor is located. UCC § 9-301(1), UCC § 9-307, UCC § 9-501(a)(2).
For as-extracted collateral, timber to be cut, and fixtures, you file locally in the county where the property is located. UCC § 9-501(a)(1). (Because they are related to real estate)
Filing is generally required for everything except: