California Code, Public Resources Code - PRC § 5003.5

The department is authorized to provide means of ingress to and egress from all state parks in order to provide ready access thereto by the public and to provide means of ingress and egress to highways and roads across state parks from lands separated from such highways and roads by state parks, and for that purpose may enter into contracts or agreements with cities, counties, and other political subdivisions of the State and with other state agencies or with persons, firms or corporations for the acquisition, construction, and maintenance of suitable roads, trails, and pathways.

When application is received by the department, other than under Section 5012, from any person, firm or corporation for right-of-way across a state park for ingress and egress to a highway or road from their lands separated from such highway or road by the state park, the department shall determine whether any reasonable access exists outside the boundaries of the park, or could be economically constructed.  Where reasonable access does not exist or cannot be economically constructed outside the boundaries of the park, the department shall grant a permit for right-of-way across the park over such route and subject to such conditions and construction and maintenance specifications as the department may determine which will cause minimum alteration to the physical features of the park and minimum interference with the use of the park by the public.  The permittee shall at his own expense construct and maintain the means of ingress and egress in accordance with the terms and conditions set forth in the permit, noncompliance with which in any part shall be due cause for revocation of such permit.  The department may require a permittee or permittees to allow the use of such means of ingress and egress by any other applicant whose lands are similarly situated.  The department shall grant a permit for such use under terms and conditions imposed upon existing users, upon payment of a reasonable compensation for construction and maintenance of the road, by the applicant to the existing permittee, or permittees.