California Code, Public Resources Code - PRC § 5873

(a) Designation of an area as a California natural landmark shall not constitute a change in the environment, as defined by Section 21060.5, and designation of an area as a California natural landmark is not a project pursuant to Division 13 (commencing with Section 21000).

(b) An action by the director or the department pursuant to this chapter modifying or rescinding the designation of a California natural landmark shall be exempt from the requirements of Division 13 (commencing with Section 21000).

(c) If the designation of an area as a natural landmark is referenced or referred to in a document prepared pursuant to Division 13 (commencing with Section 21000) for a project in or near a designated area, the designation shall not be considered part of the environment pursuant to Section 21060.5, or in evaluating the “significant effect on the environment” of that project pursuant to Section 21068.