They vary in length, but as your question is posted in the KY Derby category I will say one and one quarter miles since the Derby is held at Churchill Downs and that is the length of that particular course.
The race track can be a any size, but a hose race will usually be 1 mile, 1 1/4 mile, 1 1/2 mile. Quarter horse races are the shortest: 1/4 mile.
1 mile
John Brunetti is the current owner of Hialeah Park Race Track.
Secretariat.
horse, track, race, whip, saddle, bridle, jockey, hooves, nostrils...etc.
Ruffian was and secretariat was king
2 furlongs
The "Prix de l'arc de triomphe" is run on the horse race track of Longchamp, West of Paris.
Dirt sand and clay
The Hawthorne Race Track
You race around a track in a horse and cart
Yes, technically there is a horse racing track in Laredo Texas. It is called Laredo Race Park, it is a class 2 racetrack. It is licensed, but has not been constructed yet.
There's no specifics for a horse racing track. Horse race track dimensions vary according to the style of racing, the distances and the type of events as per the country's racing code.