While the Breeders’ Cup Marathon field remains in flux, three horses have earned a berth in the 1 3/4-mile dirt race by winning BC Challenge races. A.U. Miner won the $240,000 Greenwood Cup on July 17 at Philadelphia Park; Temple City captured the Grade 3 Cougar II Handicap on July 30 at Del Mar; Eldaafer won the Grade 3 Turfway Park Fall Championship on Sept. 11. The Grade 3, $500,000 BC Marathon will be run in 2010 for the third time, and for the first time on dirt. The race was run on the synthetic surface at Santa Anita the first two years. Both were won by European imports – Muhannak in 2008, followed by Man of Iron in 2009. Prior to the BC, Muhannak and Man of Iron previously ran in the Diamond Stakes on the all-weather track at Dundalk in Ireland, a Group 3 that is scheduled for Friday. The race is the fourth and final BC Challenge race for the Marathon; favorite Gitano Hernando is not being considered for the Breeders’ Cup. Temple City runs Saturday at Hawthorne in the Grade 2 Hawthorne Gold Cup, his first start since a sixth-place finish Aug. 28 in the Pacific Classic at Del Mar.