Black Chasm Cavern, National Natural Landmark

Black Chasm Cavern was designated a National Natural Landmark in 1986 by the National Park Service, due in part to its incredible display of rare helictite formations. It has been open for public tours since 1998.

Cave speleothems are generally formed by dripping or splashing water, but helictites are formed through hydrostatic pressure. Basically, water is pushed through porous walls leaving crystallized minerals on the other side. As the mineral deposits build up they tend to stack horizontally resulting in the incredible spun glass effect that can be seen in the Landmark Room on the walk tour.

Part of the tour takes visitors across a bridge giving small glimpses of the naturally blue lake below.

Guides talk about the early history of the cave and its unique geology. This is a fairly easy tour although there are quite a number of stairs involved and its definitely worth seeing how beautiful the Sierra Nevada are on the underside!

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Latitude: 38.4322784 Longitude: -120.6262028 Elevation: 2221 ft
the best travel advice comes from the people who live here
Lisa Boulton

Recreational Opportunities

50-minute guided walk tours are available year round. Above ground visitor center, gift shop and gemstone mining and gold panning flumes.

Seasons Accessible

Walk tours are given every day, year round.


2011 walk tour fees: Adult $14.25, Child $7.15


We always have to bring our guests to Black Chasm. They love it! The tour leads into beautiful caverns with exquisite and globally unique features. It is a very well spent hour-long journey into the earth. Do not miss it!

Rebecca Brown, 7/18/2010

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