Moaning Cave
Map SatelliteTypical of the numerous caves in the limestone of the Calaveras Formation, this cave is readily accessible. It takes its name from the moaning sound that once emanated from its entrance; the sound is not heard today.
The cave is approximately 102 meters (334 feet) deep and has several rooms. The main room is some 36 meters (120 feet) high, 27 meters (90 feet) long, and 15 meters (50 feet) wide at the maximum. There are smaller rooms below. Early explorers described another room at least as large as the main room directly beneath it; however, it has not been rediscovered. In the main room there is an 8-meter (27-foot) high speleothem (a secondary mineral deposit formed by the action of ground water) and stalactites up to 5 meters (16 feet) long. The temperature is a nearly constant 15°C (59°F).
Limestone in the Calaveras Formation was probably laid down in the late Paleozoic and was covered by later sedimentaries and volcanics which were uplifted during the Sierra Nevadan orogeny in the Jurassic. The cave, which was formed by ground water dissolving the more permeable limestone, probably dates to the late Pleistocene or perhaps early Holocene, with the melting of the Sierran glacier.
Integrity: The cave has stairs but is otherwise undeveloped.
Use: Operated commercially.
Ref: Short, H. W. 1970. The Geology of Moaning Cave, Calaveras County, California. Bull. Nat. Speleol. Soc. Vol. 32 (2), pp. 27-40.
November 1975
Inventory of California Natural Areas
Revision © 2009 Steven Louis Hartman