California Code, Business and Professions Code - BPC § 19487

Notwithstanding Section 19485, any licensed racing association operating a racetrack may construct another track of not less than one-half mile in circumference or length partially or entirely in the infield of such track, if prior to the beginning of construction or preparation of such track for horse race meetings, the board has determined upon application, in such form as it may require, that the conduct of horse race meetings at such track will be in the public interest and subserve the purposes of this chapter.  A license may be granted to any harness racing association to conduct a harness racing meeting upon such a track of less than one mile.