South of Orlando and northwest of Okeechobee, the 45,000 acre Kissimmee Praire State Preserve has 40 miles of dirt roads and doubletrack open to mountain bikers.
To reach the park from Okeechobee, head north on SR15/US441 to SR724. Turn left heading west on SR724 (Eagle Island Road) to the park.
Keep an eye out for alligators, and unexploded WWII ordinance.
Overall, Kissimmee Praire State Preserve is the 13th most popular mountain bike trail of all 58 mountain biking rides in Florida.