The L.A. County Fair was first held on Oct. 17, 1922, and ran for five days through October 21, 1922, in a former beet field in Pomona, California. Eating at L.A. County Fair is a unique experience. With more than 300 choices, undue the top button on your pants and dive in. If you're a little nervous, they do have yogurt, smoothies, fruit and salads, too!.