Planning for The American Dream Derby, the first reality television program based on horse racing, is well under way in advance of a three-week shoot set to begin Oct. 31, officials with The Network For Games (GSN) said.GSN, which is available in about 57 million homes on cable and satellite television, will hold a casting call Oct. 2 at Santa Anita Park, where the program will be based. GSN is seeking people ages 20-71 with varying levels of knowledge and interest in horses and horse racing.The casting call is set for 10:30 a.m.-2:30 p.m. PDT.The American Dream Derby calls for 12 contestants who will observe horses' daily routines, training, and personalities, and play the game by selecting the right horse. They will be taught how to handicap and wager, because any money they win could help them buy a spot in the final event.There are seven pre-recorded episodes planned for the show, which is scheduled to end Feb. 21 with a live finale at Santa Anita that will feature a horse race. Top prize is a racehorse and a potential cash prize of $250,000."It's a lot harder than we thought," said Cindy Ronzoni, vice president of publicity and corporate communications for GSN. "We're casting horses as well as people."GSN hopes to line up about 20 horses just in case there are setbacks. California-based trainer Ron Ellis is assisting with that end of endeavor as a consultant, Ronzoni said. Santa Anita general manager Chris McCarron and the National Thoroughbred Racing Association also have lent support, she said.GSN has received about 500 applications, and the deadline for applications was extended through Oct. 8.Not all the details are in place, but Joel Chiodi, executive director of marketing and promotions for GSN, said the live televised finale has the potential to be a major promotion for Santa Anita. The finale is scheduled for President's Day weekend.The show is designed to entertain as well as educate viewers on the finer points of horse racing, training, and breeding. "Unless you're with a friend, (the racetrack) can be intimidating," he said. "Part of what we're doing is bringing the intimidation factor down."Ronzoni said the network hopes the reality series is a success and can be offered each year. "It's the largest show we've done," she said. "It's the signature piece of what we want to be."GSN programming includes reality series, casino games, game shows, documentaries, and special events.