California Code, Business and Professions Code - BPC § 19608.4

A satellite wagering facility, an organization established pursuant to Section 19608.2 or any of their subcontractors or entities under contract to perform any of the functions specified in this article shall, as a condition of operating, enter into a written contractual agreement with the bona fide labor organization which has historically represented the same or similar classifications of employees at the nearest horseracing meeting.  Permanent state or county employees and nonprofit organizations who have historically performed certain services at county, state, or agricultural district fairs may continue to provide those services notwithstanding this section.