Cal. Code Regs. tit. 4, § 1813
The association shall provide one race on each racing day which is limited to California-bred horses. If, however, sufficient competition cannot be had among horses of that class on any day, it may be canceled with the approval of the stewards. The stewards shall report to the Board the cancellation of such race and the reasons therefore.
1. Editorial correction removing misplaced text (Register 2021, No. 52).