Oak Tree Directors

In addition to their membership on the Oak Tree Racing Association’s Board of Directors, the directors share a common bond—each has been an owner and breeder. That involvement furnishes a valuable perspective to their service on the Oak Tree Board.

Sherwood C. Chillingworth
Director & Executive Vice-President
Vice President and Director, Oak Tree Racing Association, since November 1989 . . . Executive Vice President since January, 1993 . . . Formerly Vice Chairman & CEO, Santa Anita Realty Enterprises, Inc. (1994-1996) . . . President of Chillingworth Corporation, a Pasadena-based real estate company . . . Past Director, Bay Meadows Operating Co.; Hillsides Home for Children; Endowment Fund Church of Our Savior; The Brown Co.; Lexitron Corporation; Luz International; Stanford University Athletic Board . . . Past Member of Board of Stewards, The Jockey Club . . . Management Committee, Equibase Corp. . . . Director of NTRA Enterprises . . . Director & Secretary of TRA . . . Served in World War II with United States Navy . . . Resides in Arcadia.


Thomas R. Capehart
Director, Vice President & Secretary
Elected to Oak Tree Racing Association Board of Directors in April, 1995 . . . Insurance executive and life member of the Million Dollar Round Table . . . Past President of Los Angeles 20th Century Roundtable; Board of Directors, Big Brothers of Greater Los Angeles; Pasadena Estate Planning Council, and Winners Foundation . . . University of Southern California Football Alumni Association and Committee . . . Active owner and breeder; Partner in Valley Creek Farm located in Valley Center, California . . . Member of The Jockey Club . . . Member of the Annandale Golf Club and El Dorado Country Club . . . Married to former Karen King . . . Resides in Pasadena.


Dr. Rick Arthur
Director, Vice-President & Assistant Secretary
Elected to Oak Tree Racing Association Board of directors in February, 2001 . . . After 30 years of Southern California racetrack practice, became Equine Medical Director at the School of Veterinary Medicine at UC Davis providing advice to the CHRB on drug testing and horse welfare and safety issues. . . . Member and past president of American Association of Equine Practitioners (AAEP) and the Southern California Equine Foundation (SCEF) . . . Director, Grayson/Jockey Club Research Foundation and the Racing Medication & Testing Consortium . . . Member, American Veterinary Medical Assn., California Thoroughbred Breeders Assn. (CTBA), Thoroughbred Breeders and Owners Assn. (TOBA), Jockey Club . . . Active in national medication and drug-testing issues for many years . . . Resides in Sierra Madre.


John H. Barr
Director & President
Named Oak Tree Racing Association President early 2011... Named to Board of Directors in May, 1997 . . . Orange County real estate developer specializing in industrial and mobile home parks . . . Races under the nom de course of Oakcrest Stable . . . Current director and past president of California Thoroughbred Breeders Association. Current member of The Jockey Club National Thoroughbred Safety Committee. Trustee and Secretary-Treasurer of the Richard Nixon Library & Birthplace Foundation. Past member of Board of Stewards of The Jockey Club…Past director of Breeders’ Cup Ltd… Served in U.S. Army.. Native of California, resides with wife Betty in Orange, CA.


Richard Mandella
Director & Vice-President
Named to the Oak Tree Racing Association Board of Directors in November, 2006 . . . Enshrined into Thoroughbred Racing’s National Hall of Fame in 2001, Mandella becomes the first-ever trainer selected to serve on Oak Tree’s prestigious Board of Directors . . . Will celebrate his 59th birthday on Nov. 5 and has been operating a public stable for 33 years . . . Attained Breeders’ Cup immortality at Oak Tree in 2003, when he saddled the winners of four of the eight Breeders’ Cup races that day. The feat is regarded by many as the sport’s greatest single-day training achievement . . . Also recorded the only one-two-three sweep in the history of the Santa Anita Handicap, with Siphon, Sandpit and Gentlemen in 1997 . . . Has won two Oak Tree training championships and ranks sixth all-time at Oak Tree with 178 wins. He is tied for third in career stakes wins with 42 . . . Has also distinguished himself by devoting considerable time and effort through service on various panels and boards dedicated to improving racing surfaces, medication, necropsy, and improvement of backstretch housing . . . Resides in Pasadena with wife Randi and daughter Andrea . . . Son Gary operates his own public stable.


Warren B. Williamson
Director & Vice-President
Elected to Oak Tree Racing Association Board of directors in August, 2007 . . . Introduced to the equine world at an early age through visits to the family’s 4,200-acre ranch near Ramona . . . He became an owner in the late 1960s but his stable’s orange and yellow silks gained national prominence through the success of Nashoba’s Key (recently deceased) . . . Graduate of Claremont Men’s College in 1951 . . . Served two years in the army before beginning career as a stockbroker . . . Joined the firm of Crowell Weedon & Co. in 1970 and became a General Partner in 1976 . . . Involved in executive capacities of numerous philanthropic organizations in the San Gabriel Valley . . . Resides in Pasadena with wife, Alyce.


Robert W. Zamarripa, Sr.
Director & Vice-President
Elected to Oak Tree Racing Association Board of directors in August, 2007 . . . He is a native Angelino, now making his home in Monrovia . . . Part owner of multiple stake winner, Jungle Prince, third behind Bordonaro in the Grade I Ancient Title Stakes at Oak Tree in 2006 . . . Since the passing of his wife, the father of four has increased his racing interests . . . Following his graduation from Pasadena College in 1955 he began a career in the field of electrical wholesale distribution, which ultimately led to his purchase of Los Angeles Wholesale Electric in 1983 . . . A subsequent expansion into the San Diego area in 1986 prompted “Bob” to turn over the reins of the operation to his son Bob Jr. and the company became known as One Source Distributors.