Jewel Cave National Monument: 180 miles (so far) of underground adventure

Jewel Cave is the third-longest documented cave on Earth.

So far, 180 miles of cave have been found, but experts think Jewel could extend as far as 5,000 miles.

Mapped routes are displayed at the Jewel Cave National Monument visitors center.

Examples of rock and mineral formations are on display at the visitors center.

Park ranger and tour guide Brad Yoder greets visitors before the group takes an elevator down to the cave.

Park ranger and tour guide Brad Yoder, center, escorts a group to the elevators that will bring the tour to the cave.

Park ranger and tour guide Brad Yoder brings visitors to the entrance of the cave via a 239-foot elevator ride.

Park ranger and tour guide Brad Yoder guides visitors through the cave.

Forty-two flights of stairs help to guide more than 70,000 annual visitors to the cave.

Visitors explore Jewel Cave’s vast network of tunnels.

Jewel Cave is a discovery in progress.

The majority of Jewel Cave’s passages were formed about 65 million years ago.

Jewel Cave’s geologic features include stalagmites and stalactites, a variety of crystals and rare silver-colored globules called hydromagnesite balloons.

Park Ranger and tour guide Brad Yoder turns off all visible light before using a single flame to show how early visitors and explorers saw Jewel Cave.

There are hidden gems throughout Jewel Cave.

The incredibly winding and intricate layout of routes and openings have been formed by the slow movement of water seeping through sandstone on the surface.

The wind and water create beautiful rock formations underground.

Two permanent camps have been established in the cave so that teams of explorers are able to work from the base camps, as it takes between seven and nine hours to reach the sites.

Just 30 miles from Jewel Cave, Wind Cave National Park features the sixth-longest documented cave on Earth, with 145 miles of passages. Above the cave, the park’s nearly 500 bison graze in the straw-colored grasslands.