Cal. Pub. Res. Code § 5008.1

(a) When it is determined by the director to be in the public interest, and subject to the fees, rules, and regulations of the department, visitors to units of the state park system may bring animals into those units.
(b) Any animal brought into a state park system unit pursuant to subdivision (a) shall be under the immediate control of the visitor or shall be confined, and under no circumstance shall the animal be permitted to do any of the following:
1. (1) Pose a threat to public safety and welfare.
2. (2) Create a public nuisance.
3. (3) Pose a threat to the natural or cultural resources of the unit or to the improvements at the unit.
(c) The department may require a person bringing an animal into a state park system unit pursuant to subdivision (a) to provide proof of appropriate immunizations and valid licenses.
(d) This section does not apply to dogs used to lawfully pursue game in season at units of the state park system where hunting is allowed.
(e) No later than July 1, 2020, the department shall establish and maintain on its Internet Web site a comprehensive, up-to-date list of each state park system unit with information on whether the unit or a portion of the unit allows dogs and additional information that may include, but is not limited to, the specific areas of the unit in which dogs are allowed and the total miles of trail in the unit that are open to dogs.