July 7, 2006—Beneath the mountains of Nevada's Great Basin National Park lies a deep, dark secret—a little-known network of caverns known as Lehman Caves.

Relatively few tourists visit the caves each year, but even a small trickle of traffic is enough to pose a threat to the caves' delicate limestone formations.

Explore the fragile natural wonder of Lehman Caves, and learn how park rangers are working to strike a balance between preserving the caverns and sharing them with the world.