California Code, Public Resources Code - PRC § 5016.1

In order to exchange certain lands patented to the State of California for park purposes situated outside and within 10 miles of the exterior boundaries of the Anza-Borrego Desert State Park for the purpose of acquisition of other public domain lands needed for park purposes still within these boundaries as well as elsewhere in the state, the department is authorized to exchange such lands for lands of approximate equal value which may be made available for park purposes by the federal government.  In making the exchanges the department may comply with all rules prescribed by the Secretary of Interior relating thereto.