Black Hills Caves

Over 100 caves can be found in the limestone encompassing the Black Hills. Many of these caves are just a few hundred feet or less in length, while others are much longer.

Jewel Cave was discovered west of the city of Custer in 1900. It contains more than 84 miles of underground passages, making it the second longest cave in the country. Jewel Cave is the fourth longest cave in the world.

Wind Cave (found north of Hot Springs in 1881) spans over 65 miles in length. This is the third longest cave in the U.S. and the seventh longest in the world. Experts studying it have discovered that less than 5% of Jewel Cave and Wind Cave have been explored by human beings. How do scientists determine this? They calculate the volume of air entering and leaving the cave, and use these measurements to estimate the cave volume (about 2 billion cubic feet).

The Black Hills caves are important for more reasons than their enormous size. They are also the world's oldest, according to leading experts in the field. The Wind and Jewel Caves probably began to form 40 to 60 million years ago.