Cal. Rev. & Tax. Code § 8653
No tax shall be imposed upon any user with respect to that fuel which the user establishes to the satisfaction of the board is used in the operation of a motor vehicle off the highway.
Source: view the official text
No tax shall be imposed upon any user with respect to that fuel which the user establishes to the satisfaction of the board is used in the operation of a motor vehicle off the highway.
Source: view the official text