The Del Mar Fairgrounds is a 370-acre (1.5 km2) property that is the site of the annual San Diego County Fair (called the Del Mar Fair from 1984 to 2001). Its Del Mar racetrack was built by the Thoroughbred Club in 1937 by founding members Bing Crosby and Pat O'Brien with Paramount Studios as corporate sponsor.The fairgrounds is owned by the State of California and is managed by 22nd District Agricultural Association, a state agency that hosts more than 300 annual events.