D. Wayne Lukas is easy to spot before dawn at Churchill Downs. He is one of the few Kentucky Derby trainers atop a stable pony, escorting his horses to and from the track for their workouts. At 89, he ...

Under a swath of Kentucky hills and hollows is a limestone labyrinth that became the heartland of a national park. The surface of Mammoth Cave National Park encompasses about 80 square miles.