Thursday, February 8, 2024

Black Chasm Cavern


 The geology of California goes through huge changes in relatively small distances. Sacramento sits in the Central Valley, the long flat area that stretches several hundred miles north-south, from Bakersfield to Redding, while never being more that 100 miles wide. To the west are the state’s coastal mountain range, and to the east are the Sierra Nevadas. So a drive of 50 or so miles from Sacramento will take you from the dry valley up into the lush verdant mountains, to the town of Volcano, California.


In 1854, a group of gold miners in that area, encountered the small entrance to a cave. When they explored it, they found that the cave expanded to be several chambers, the bottom ones filled with water. The walls were covered with some of the most beautiful cave formations, called helictites. Most of us are familiar with stalactites, which grow up from a cave’s floor, and stalagmites, which grow down from the cave’s roof. Helictites are small crystals, that have grown in random directions, twisting and curving every which way. No one is exactly sure how they form, one theory is that capillary forces play a role. Only 5% of caves have helictites,  and the cave discovered in Volcano has the largest collection in the United States. The miners named the cave Black Chasm Cavern, and offered tours, for a fee.

Black Chasm Cavern Visitor's Center


As the gold rush ended, the cave fell into disuse, and the land was sold to the first of several companies that mined the mountain for gravel to use in making concrete. Black Chasm Cavern was rediscovered in the 1950’s. Luckily, it was on the side of the mountain that had not yet been turned into a quarry. Cavers and geologists spent time exploring the cave, sometime offering tours to the public, but it was not yet developed, and it was a tough tour, using ropes and harnesses. In 1975, workers from the National Park Service entered the cave for the first time, and the presence of the helictites convinced them to designate the cave as a National Natural Landmark. This does not make it a national park, and the cavern is run by a private entity, but the land does have a protected status. 

Small Stalactites

Tree roots reaching underground


In 1996, the Sierra Nevada Recreation Corp began working with Gold Country Adventures to develop and run tours at Black Chasm Cavern. They expanded the entrance, and built stairs and platforms to make exploration easier for visitors. The safe passage descends to a depth of 100 feet below the surface, and visitors must use 160 stair steps in each direction to take the tour. There is also a 3000 sq. Ft. visitor’s center, where tickets are sold, along with snacks, and souvenirs. Our guide for the 50 minute tour was very knowledgeable and worked well with all members of our group.





Before or after your tour, take a walk along the Miner’s Trail, and explore the effect that gold mining had on the mountain. In the 1850’s “Hydraulic Mining” was used to free up the ore near the surface. High pressure water was used to wash away the top-soil, leaving behind marble monoliths, especially in a the bed of a dry creek. You can wander through these large stones, and explore the area.

Nuts and Bolts:

The Black Chasm Cavern National Nature Landmark is 59 miles southeast from Sacramento. Tour tickets are $21 for adults/ $13 for children (5-12). Tour run every hour, limited to 20 participants. They are first come-first serve - no reservations are taken. Be prepared to 1 - 2 hours depending on the number of visitors.


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