Here is the official State of California Fairs list
(not to be confused with list that contains additional fairs in California)

California Fairs aren't just limited to the traditional County Fair, though these events in California are extremely popular with some getting over one million people attending each year. There are 58 counties in California and 78 fairs operated under the guidelines of the Department of Food and Agriculture - Division of Fairs and Expositions. This agency also manages the permitting of horse racing operations. Here is the list of fairs with horse racing and wagering.

Live Racing Fairs:

* Alameda County Fair, Pleasanton
* California State Fair, Sacramento
* Fresno District Fair, Fresno
* Humboldt County Fair, Ferndale
* Los Angeles County Fair, Pomona
* San Joaquin County Fair, Stockton
* Sonoma County Fair, Santa Rosa

Satellite Wagering Fairs:

* Antelope County Fair, Lancaster
* Desert Empire Fair, Indio
* Fresno Club One, Fresno
* Kern County Fair, Bakersfield
* Lake Perris Sports Pavilion, Perris
* Monterey County Fair, Monterey
* National Orange Show, San Bernardino
* San Bernardino County Fair, Victorville
* Santa Barbara County Fair, Santa Maria
* Santa Clara County Fair, San Jose
* Shasta District Fair, Anderson
* Stanislaus County Fair, Turlock
* Surfside Race Place, Del Mar
* Ventura County Fair, Ventura
* Tulare County Fair, Tulare