California Code
ARTICLE 4.5 - Alteration of Boundaries
Section 23258.

23258. Boundary lines between counties may not be changed if as a result of such change: (a) a strip of untransferred territory less than 200 feet wide and more than 300 feet long is created; (b) a strip of untransferred territory consisting solely of a highway or portion thereof is created; or (c) the territory of any incorporated city is divided.

(Added by Stats. 1974, Ch. 1393.)