California Code, Public Resources Code - PRC § 4156

(a) The director and employees or classes of employees of the department designated by the director have the powers conferred by law upon peace officers listed in Section 830.2 of the Penal Code, and voluntary firewardens designated by the director have the powers conferred by law upon peace officers listed in Section 830.37 of the Penal Code; provided, however, that the primary duty of the peace officer shall be the enforcement of forest laws and regulations, state and county fire laws and regulations, and the laws relating to explosives as set forth in Part 1 (commencing with Section 12000) of Division 11 of the Health and Safety Code, other than laws the enforcement of which is primarily the responsibility of the State Fire Marshal. Officers, employees, and voluntary firewardens, upon request pursuant to Section 8597 of the Government Code, shall have the full powers and duties of peace officers for all purposes as provided by the Penal Code and are not liable to civil action for trespass committed in the discharge of their duties.

(b) A peace officer may enforce federal fire laws to the extent that the peace officer is authorized to do so.