One
of the treats we had planned for our 2024 Black Hills trip was a tour of Jewel
Cave. We’d toured neighboring Wind Cave last spring and Jean was comfortable
being underground, so we expected the same at Jewel Cave. First some logistics.
Since the main season hadn’t started, the 80 minute Scenic Tour was our only
option. In the past I had taken the Discovery (the park’s shortest) and Wild
Cave (the park’s most rigorous) tours, but still lacked the opportunity to take
the Historic Lantern Tour. All the tours are popular and advanced reservations
are needed, so we signed up via Recreation.gov. For 2024, tours at Wind Cave
were suspended due to work on the replacement of the elevator, creating some
extra demand at Jewel Cave.
Jewel Cave NM map with trails and cave routes.
Our
tour started at 9AM with a quick safety tour from our ranger/guide. There were
about 30 people on the tour, a small enough group that it was possible to hear
the ranger at each stop. The first leg was the elevator ride down to the Target
Room. We would tour a route that was pioneered by the legendary cave explorers
Herb and Jan Conn. Our guide would do a spectacular job interpreting the
geology and history of the cave at another half dozen stops along the way.
Photography was allowed along the route, but it is tough to take pictures with underground
lighting. 
Cross section of a crystal filled cave passage with bands of nailhead spar.
Jewel
Cave currently has 220 miles of explored passages, and is the fifth longest
cave in the world. Its beginnings were modest, the known passages were only a
few miles long when the Conns and others began serious exploration of the cave.
Besides its size, the cave is known for its namesake feature, the jewels of
calcite crystals that line much of the cave.
Nailhead spar, the jewel of the cave.
After
dissolution of the cave, its sandstone cap was breeched but the cave passages
remained filled with water. This water lost its acidity and began to
precipitate calcite crystals on the cave walls, essentially turning the cave
into a giant geode. The final stage in cave formation was the draining of the
water, and the local collapse of rock into some rooms and passages. Our guide
told us the cave has the largest amount of nailhead spar (the crystalline form
of calcite that makes the “jewels”) in the world, and may have even more
boxwork formation that Wind Cave, considering the boxwork that may be hidden
underneath the jewel layer.
Ladders and rails.
Our
route went through Rum Runners Lane, the Formation Room, the Mezzanine, as well
as Spooky Alley and the Torture Room, where the thirsty Conns were taunted with
the dripping of water that they could not reach. We saw one slice of cave
bacon, an unusual cove formation named for its stripes.
Cave bacon.
We
also stopped at the New Wet Room where the construction of the cave elevator
had allowed water seepage which was depositing new formations giving the park
new insight into the rate at which these cave formations form. We also heard an
update on current cave exploration which was now being carried out from an
underground camp due to the amount of time needed just to reach the start of
the new areas.
Boxwork in the cave walls.
The
tour followed a concrete path with railings and a well-publicized 700+ steps. The
NPS had done a great job of confining the impact of near constant tours to a
small area within the cave. Hopefully, I’ll get back there in midseason to
finally take one of the lantern tours.
An overlook of the tour route.
Jewel
Cave is a small Monument, but does have a 3.5 mile long hiking trail on the
surface. But Jean and I felt a little more ambitious, and drove across US 16 to
the BHNF’s Hell Canyon Trail, where we hiked a six mile long loop (Hell Canyon) under clear blue
skies.
After
our Hell Canyon hike we went back to the Jewel Cave visitors center to check
out the displays and watch the park film. We had just finished with the small
display area when I checked the weather and noticed a storm cell heading
straight for the Monument and on the way to Custer. I thought we could sit out
a quick down pour when Jean heard a report of potential two inch diameter hail!
We quickly headed for the parking lot where it had already started to rain. We
realized that if we returned to Custer we would be in the cell the entire
drive, and if we turned the other way we would be racing through the storm
front at maximum speed, so we decided to wait out the storm in our Forester.
Hail on our hood.
After
a first round of heavy rain, we got a second round of heavy slush followed up
by pea-sized hail. The slush was unusual, just splatting on the car and
windshield, usually precipitation is liquid or solid, not in between. Luckily,
the cell was small. The storm lasted less than 30 minutes, though it seemed
much longer. But soon the skied clear and we began clearing an inch of slush
and hail off the car. Not as much was piled up on the warm ground. What a
switch from the canyon mere minutes before, where we’d hugged what little shade
we could find to stay cool. And what a surprise would await those on the cave
tour who would emerge to blues skies and this wintery wonderland.
It was sunny just a few minutes ago.
Forgetting
all about the park movie, we trailed the storm back to Custer watching the depth
of snow on the few cars coming west, and the drifts of slush and hail along the
side of the road. 
A miniature snowman.
