California Code, Streets and Highways Code - SHC § 154

The department shall encourage the construction and development by counties of portions of the county highways as official county scenic highways and may furnish to the counties any information or other assistance which will aid the counties in the construction or development of such scenic highways.

Whenever the department determines that any county highway meets the minimum standards prescribed by the department for official scenic highways, including the concept of the “complete highway,” as described in Section 261, it may authorize the county in which the highway is located to designate the highway as an official county scenic highway and the department shall so indicate the highway in publications of the department and in any maps which are prepared by the department for distribution to the public which show the highway.

If the department determines that any county highway which has been designated as an official county scenic highway no longer meets the minimum standards prescribed by the department for official scenic highways, it may, after notice to the county and a hearing on the matter, if requested by the county, revoke the authority of the county to designate the highway as an official county scenic highway.