Our first stop in the Black Hills – and South Dakota – is another cave, Jewel Cave. It is clearly more popular than either of the two caves we’ve visited so far: we cannot get tickets for the tour we had hoped for. Fortunately we don’t have to wait too long; they offer tours every 40 minutes. Our tour is packed, and not all of the people are to our liking. Our tour guide is very good, though, knowledgeable and helpful.
This cave is interestingly different from the tours we’ve seen earlier on this trip. It is mostly dry (and hence not longer ‘live’), at least in many of the parts we get to see. Jewel Cave is currently thought to be the second longest cave in the world (~ 157 miles), and we only get to see a very small fraction of it. Some of the chambers of the cave are remarkably large, too.
The most distinctive feature of Jewel Cave, however, are the “jewels”. The jewels in question are calcite crystals, of no particular value, but nice to look at. Or nice to look at when they are clean. Most of the crystals are covered in dust, so “jewel” is not what immediately springs to my mind. In some chambers they cover the entire walls, giving them an appearance of something very prickly – perhaps a lychee.
It is certainly a very unusual cave, and one that is still being explored today. According to our guide, analysis of windflow in the cave indicates that only 5 – 10% of the volume of the cave has been discovered so far, so there’s plenty for the volunteer explorers who are mapping it still to discover.
The visitor center sells maps of the cave – they come in two different sheets, to capture the expanse of the cave, and the different levels. They also offer spelunking tours, which we would love to go on, but the logistics of such a tour are beyond what we could fit into our schedule. To be allowed on the spelunking tour, a test must be passed: outside the visitor center sits a concrete block, with an opening in the middle. Only those who manage to squeeze through that opening are allowed on the spelunking tour. Of course I have to try it out. Success, I’d be good to go! My only competition are some 8 year olds, who would be disqualified for age reasons anyway! But maybe that just goes to show that I have more in common with an eight year old than an average adult.