Borrego was bred to sell by a partnership Jon Kelly, Ralls and Foster LLC, Brad Scott and C. Beau Greeley.
Greely started Borrego on the road to the Kentucky Derby in 2004, first in the Sham Stakes at Santa Anita Park.
Greely shipped Borrego across the country for the Grade 1 Jockey Club Gold Cup at Belmont Park.
Under regular rider Garrett Gomez, dropped back to his usual position near the rear of the pack early before unleashing a rally en route to an effortless 4½ length win.
Borrego's final career race was the Breeders' Cup Classic, also held at Belmont that year, but he was unable to replicate his previous efforts as he ran 10th.