California Code, Labor Code - LAB § 3365

(a) Except as provided in subdivisions (b) and (c), each person engaged in suppressing a fire pursuant to Section 4153 or 4436 of the Public Resources Code, and each person (other than an independent contractor or an employee of an independent contractor) engaged in suppressing a fire at the request of a public officer or employee charged with the duty of preventing or suppressing fires, is deemed, except when the entity is the United States or an agency thereof, to be an employee of the public entity that he is serving or assisting in the suppression of the fire, and is entitled to receive compensation from such public entity in accordance with the provisions of this division. When the entity being served is the United States or an agency thereof, the State Department of Corrections shall be deemed the employer and the cost of workers' compensation may be considered in fixing the reimbursement paid by the United States for the service of prisoners. A person is engaged in suppressing a fire only during the period he (1) is actually fighting the fire, (2) is being transported to or from the fire, or (3) is engaged in training exercises for fire suppression.

(b) A member of the armed forces of the United States while serving under military command in suppressing a fire is not an employee of a public entity.

(c) Neither a person who contracts to furnish aircraft with pilots to a public entity for fire prevention or suppression service, nor his employees, shall be deemed to be employees of the public entity; but a person who contracts to furnish aircraft to a public entity for fire prevention or suppression service and to pilot the aircraft himself shall be deemed to be an employee of the public entity.