A Small Cave No More

Herb and Jann Conn standing in front of the Historic Entrance
Herb and Jann Conn in front of the Historic Entrance

NPS Photos

When the Michaud Brothers discovered the cave in 1900, up until 1959, only around 2 miles of cave was known. Though the cave was beautifully decorated with calcite spar crystals, the tour route was short, and some wondered whether this small cave was truly of national significance. Jewel Cave couldn’t yet boast the title of “one of the longest caves in the world”, but that would soon change.

Herb and Jan Conn moved to the Black Hills in search of adventure. They became famous rock climbers in the area, pioneering many first ascents of the Needles and Cathedral Spires of Custer State Park. Jan Conn was the first women to ever climb Devils Tower. As they climbed, they made friends with a geologist named Dwight Deal. When the Conns asked Dwight what he did in the winter when it was too cold to climb, he said, “Well, I go underground.” They were intrigued. Dwight brought them to Jewel Cave, and they fell in love with it. For the next 20 years Herb and Jan spent every spare minute they could exploring, surveying, and mapping 65 miles of the inner reaches of Jewel Cave.

Deal moved away, but the Conns pressed on. They discovered the area that would become the Scenic Tour route. Their discoveries and mapping were integral to building the new tour routes, the Scenic Tour and Discovery Tour that displayed many of the newly found formations in the cave. The Conns helped decide where to put the elevators and subsequently the Visitor Center which were constructed in the 1960s and completed in 1972.
1959 Herb & Jan Conn, Dave Schnute, and Dwight Deal in the Cave
Herb and Jann Conn (left), Dwight Deal (center), and Dave Schnute (right) in the Cave.

NPS Photo

Herb wrote a scientific paper regarding airflow in the cave. Based on pressure changes, he was able to calculate the approximate extent of the cave. Currently, there are over 217 miles of cave passage mapped. Based on Herb’s findings and ongoing research (science & research page), that accounts for less than 5% of the entire expanse of Jewel Cave. This could be the longest cave in the world, it just hasn’t been found yet.

Herb and Jan Conn were very important to the continual discovery of Jewel Cave. Their curiosity and excitement sparked the exploration bug that we still have today. They spent as much time in the cave as they possibly could and are not only remembered for their contribution to Jewel Cave but also for their never-ending kindness. Everyone that knew Herb and Jan and had the opportunity to cave with them almost always mentioned what amazing people they were. Without them, we could be telling a very different story.

Today, cave exploration continues through efforts of volunteers and park staff. Cavers can spend up to 4 days and 3 nights in the cave, exploring and mapping uncharted areas of one of the final frontiers on earth. The chance to place their foot somewhere no one in history has ever seen is what keeps them pushing forward. New formations and rooms of the cave are found on every expedition into the unknown reaches of Jewel Cave.

Last updated: October 24, 2023

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Contact Info

Mailing Address:

11149 U.S. Hwy. 16
Building B12

Custer, SD 57730


605 673-8300
The main phone line connects visitors with staff at the visitor center. Throughout the year, the phone line is monitored by staff on a daily basis, excluding holidays and days with limited visitor services. Please be advised that after-hours messages are not taken on the system; visitors are encouraged to call the visitor center during normal operations and speak with a park ranger for assistance.

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