California Code, Health and Safety Code - HSC § 41300

(a) Notwithstanding Section 40410 or any other provision of this part, that portion of the Antelope Valley that is located in northern Los Angeles County shall not be within the south coast district. That territory shall constitute the territory of the Antelope Valley Air Quality Management District, which is hereby created.

(b) The territory of the Antelope Valley district has the following boundaries: the San Bernardino County line to the east, the Kern County line to the north, the San Gabriel Mountains to the south, and the Sierra Nevada Mountains to the west. The south and west boundaries shall coincide with the boundaries of the Southeast Desert Air Basin, as determined by the state board, by regulation.