Used to live in Grove City, Ohio where Beulah Park had harness racing. Wikipedia says it was thoroughbred racing but I never saw it, only harness racing or trotters as they were known also. We used to stand near the rail and watch the horses so close you could almost touch them.
What surface do the horses race on? In NZ our harness racers (I think they are called Trotters here) race on grass.