California Code, Business and Professions Code - BPC § 19485

The board shall not issue a license to conduct a horse racing meeting at any place, track or inclosure, not used for horse racing meetings prior to July 1, 1941, unless prior to the beginning of the construction or preparation of such track for horse racing meetings, the board, upon application in such form as it may require, has determined that the conduct of horse racing meetings at such track will be in the public interest and will subserve the purposes of this chapter.

This section does not apply in respect to any track of not less than five-eighths of one mile in circumference or length partially or entirely in the infield of a mile track constructed and operated by a thoroughbred licensee under this article provided that such infield track is to be used solely for thoroughbred racing.