The board of supervisors shall have power to create a county park commission to consist of not less than five or more than seven members who shall be residents of the county. The members of such commission shall be appointed by the board of supervisors and hold office during the pleasure of the board or for such terms as the board may determine. Not more than a majority of the members of any such commission shall belong to the same political party. The members of any such commission shall serve without compensation but shall be allowed their necessary expenses incurred in the performance of their duties. Within the amount provided by appropriation and subject to such rules and regulations as the board of supervisors may prescribe, any such county park commission shall have the supervision and management of all county parks within the county. All county parks shall be kept and maintained for the free use of the public, subject to such regulations as the board of supervisors may impose.