In an effort to promote the road to the Kentucky Derby in the Derby's back yard, Keeneland and sister track Turfway Park have announced a $1-million bonus for a horse that wins three of four prep races, track officials announced Thursday.The bonus ($800,000 to the owner, and $200,000 to the trainer) will go to any horse that wins the $600,000 Turfway Spiral Stakes March 24, the $750,000 Toyota Blue Grass (April 14) or $325,000 Coolmore Lexington Stakes (April 21), and the $1-million Kentucky Derby May 5.Keeneland president Nick Nicholson told the Kentucky Racing Commission at a meeting Thursday that the money for the bonus will come from the racetracks. Keeneland owns a third of Turfway Park. He said the two tracks want to generate interest in Kentucky's road to the Derby.This year, the three big races -- the Spiral, the Toyota Blue Grass, and Derby -- are three weeks apart. The Coolmore Lexington will be run two weeks before the Derby.The only horse to win the grade II Spiral (formerly the Jim Beam Stakes) and the Kentucky Derby is Lil E. Tee, who did so in 1992. In 1999, Charismatic didn't compete in the Spiral, but he parlayed a win in the grade II Coolmore Lexington Stakes into a victory in that year's Kentucky Derby.There are other $1-million bonuses tied to the Kentucky Derby. Fair Grounds has the "Great Post Challenge," which offers a bonus to any horse that wins the grade II Louisiana Derby and the Kentucky Derby. Lone Star Park in Texas offers a bonus to a horse that wins the Lone Star Derby April 7, and either the Kentucky Derby, Preakness Stakes, or Belmont Stakes.