Artificial racing surfaces at North American racetracks trace to 1966, when Tropical Park in Dade County, Fla., introduced a rubberized surface called “Tartan Turf,” developed by Hall of Fame trainer John Nerud and Minnesota Mining and Manufacturing Co. (3M), whose chairman, William L. McKnight, owned Tartan Farm. One race per card was held on the Tartan Turf, but the vast majority of horsemen and jockeys refused to compete on the hard surface, even after tweaks were made to soften the ground. The next track to try a synthetic surface was Remington Park in Oklahoma City, which installed oil-based Equitrack in 1988. However, maintenance costs and difficulties recruiting horsemen to run at the track forced the track to go back to a dirt track in 1991. It was 14 years before synthetic racing surfaces once again emerged from the training tracks to a parimutuel facility, when Turfway Park opened its 2005 fall meet with a Polytrack surface. Within the next two years, all-weather tracks began to appear across the country, including every major track in California as mandated by the California Horse Racing Board. That policy has since been relaxed. Today, eight parimutuel racetracks in North America feature a main track comprised of a synthetic surface, in addition to the Ocala Training Center, which hosts lucrative non-parimutuel stakes races for the alumni of Ocala Breeders’ Sales Co. auctions. Those nine venues use one of four of all-weather surfaces – Polytrack, Cushion Track, Tapeta Footings, or Safetrack – consisting of different blends of silica sand, rubber, synthetic and elastic fibers, and wax coatings. North American tracks with synthetic surfaces   Polytrack Arlington Park Arlington Heights, Ill. Year installed: 2007 Track circumference: 1 1/8 miles Key main-track stakes races: Arlington Matron S. (G3), Arlington Oaks (G3), Arlington-Washington Futurity (G3), Chicago H. (G3), Hanshin Cup (G3), Washington Park H. (G3) Del Mar Del Mar, Calif. Year installed: 2007 Track circumference: One mile Key main-track stakes races: Bing Crosby S. (G1), Clement L. Hirsch S. (G1), Del Mar Futurity (G1), Pacific Classic S. (G1) Best Pal S. (G2), Cougar II H. (G2), Pat O’Brien S. (G2), San Diego H. (G2), Rancho Bernardo H. (G3), Sorrento S. (G3) Keeneland Race Course Lexington, Ky. Year installed: 2006 Track circumference: 1 1/16 miles Key main-track stakes races: Alcibiades S. (G1), Ashland S. (G1), Blue Grass S. (G1), Breeders’ Futurity (G1), First Lady S. (G1), Madison S. (G1), Spinster S. (G1), Doubledogdare S. (G2), Fayette S. (G2), Raven Run S. (G2), Thoroughbred Club of America S. (G2), Ben Ali S. (G3), Commonwealth S. (G3), Lexington S. (G3), Phoenix S. (G3) Turfway Park Florence, Ky. Year installed: 2005 Track circumference: One mile Key main-track stakes races: Bourbonette Oaks (G3), Spiral S. (G3), John Battaglia Memorial S., Rushaway S. Woodbine Rexdale, Ontario, Canada Year installed: 2006 Track circumference: One mile Key main-track stakes races: Queen’s Plate S., Autumn S. (Can-G2), Hendrie S. (Can-G2), Bessarabian S. (Can-G3), Bold Venture S. (Can-G3), Dominion Day S. (Can-G3), Durham Cup S. (Can-G3), Eclipse S. (Can-G3), Grey S. (Can-G3), Kennedy Road S. (Can-G3), Mazarine S. (Can-G3), Ontario Derby (Can-G3), Ontario Fashion S. (Can-G3), Ontario Matron S. (Can-G3), Seagram Cup S. (Can-G3), Seaway S. (Can-G3), Selene S. (Can-G3), Whimsical S. (Can-G3), Valedictory S. (Can-G3), Vigil S. (Can-G3) Cushion Track Betfair Hollywood Park Inglewood, Calif. Year installed: 2006 Track circumference: 1 1/8 miles Key main-track stakes races: Hollywood Gold Cup (G1), Triple Bend H. (G1), Vanity H. (G1), A Gleam H. (G2), Californian S. (G2), Hollywood Oaks (G2), Marjorie L. Everett H. (G2), Mervyn LeRoy H. (G2), Swaps S. (G2), Affirmed H. (G3), Hollywood Juvenile Championship S. (G3) Los Angeles H. (G3) Tapeta Footings Golden Gate Fields Albany, Calif. Year installed: 2007 Track circumference: One mile Key main-track stakes races: All American S. (G3), El Camino Real Derby (G3), California Derby Presque Isle Downs Erie, Pa. Year installed: 2007 Track circumference: One mile Key main-track stakes races: Presque Isle Downs Masters S. (G3), Fitz Dixon Jr. Memorial Juvenile S., H.B.P.A. Stakes, Inaugural S., Karl Boyes Memorial S., Presque Isle Downs Debutante S., Presque Isle Mile, Satin & Lace S., Tom Ridge S., Windward S.