Cal. Gov. Code § 8598

Whenever a local emergency exists within a region or area of the state and the Department of the California Highway Patrol or the Department of Corrections or the Department of the Youth Authority employing any peace officer within Section 830.5 of the Penal Code is requested by properly constituted local authorities to assist local law enforcement, the officers assigned to assist within the designated regions or areas shall have the full powers of peace officers within the meaning of Section 830.1 of the Penal Code and shall perform those duties and exercise those powers as are appropriate or as may be directed by their superior officers.