California Code, Public Resources Code - PRC § 5558

(a) The board shall superintend, control, and make available to all of the inhabitants of the district, subject to its ordinances, rules, and regulations, all public parks, playgrounds, beaches, parkways, scenic drives, boulevards, open spaces, and other facilities for public recreation belonging to the district or under its control.

The board shall regulate, restrain, and control the kind of vehicles, and the time and conditions of travel or parking on such public parks, playgrounds, beaches, parkways, scenic drives, boulevards, open spaces, and other facilities for public recreation, and it shall employ a suitable police force and shall adopt all ordinances, rules, and regulations necessary for the administration, government, protection, and use of the property, improvements, and facilities belonging to the district or under its control.

The board shall, in general, do all acts necessary to the proper execution of the powers and duties granted to, and imposed upon, it by this article, and to manage and control the business and affairs of the district.

(b) Notwithstanding any other provision of this section, the board of any district organized pursuant to Sections 5506.5 and 5538.5 may designate and employ officers and employees of the county in which the district is located as the district police force required by this section.