California Code, Streets and Highways Code - SHC § 951

(a) Such board may set apart on any county highway a strip of land for a side path, and make an order designating the width of such path, and cause the lines separating the path from the highway to be located and marked by stakes, posts, curbs, dikes, trees, or other physical delineations, placed at such distances apart as the board considers proper.

(b) After a path is set apart, and the lines separating it from the highway are located and marked, as provided in subdivision (a) of this section, the use of such path is restricted to pedestrians, riders of horses, and riders of vehicles propelled solely by the power of the rider.

(c) The board may charge the expense of erecting and maintaining such path to the county general fund, the road fund, or the district fund of any district benefited.