Moaning Caverns

Useful Information

Location: In Calaveras County between Vallecito and Columbia State Park on the Parrotts Ferry Road. Near Hwy 49.
Open: Spiral Tour: JAN to MAY daily 10-16.
JUN to AUG Mon-Fri 9-17:30, Sat, Sun 9-18.
SEP to DEC daily 10-16.
Thanksgiving: 10-13.
Christmas Eve: 10-13.
Christmas Day: closed.
New Year’s Eve: 10-16.
Times are first and last tour, tours every hour.
Expedition Tour: all year after appointment.
Fee: Spiral Tour: Adults USD 20, Children (6-11) USD 15, Children (0-5) free.
Expedition Tour: Adults USD 95, Children (0-11) not allowed.
Classification: SpeleologyKarst Cave marble of the Calaveras Formation
Light: LightIncandescent Electric Light System
Dimension: VR=125 m, T=16 °C.
Guided tours: Spiral Tour: D=45 min., St=235, VR=50 m.
Expedition Tour: D=2-3 h.
V=100,000/a [2000]
Photography: allowed
Accessibility: No.
Bibliography: Phil C. Orr (1952): Excavations in Moaning Cave, Santa Barbara, Museum of Natural History, Dept. Anthropol. Bull. No. 1 (1952).
Anonymous (1953): Notes and News. American Antiquity, vol. 19, no. 1, 1953, pp. 100–108. JSTOR.
Wallace S. Broecker, Edwin A. Olson, Phil C. Orr (1960): Radiocarbon Measurements and Annual Rings in Cave Formations Nature volume 185, pages 93–94 (09 January 1960) Nature.
Address: Moaning Caverns Adventure Park, PO Box 78, Vallecito, CA 95251 or 5350 Moaning Cave Rd., Vallecito, CA 95251, Tel. +1-209-736-2708 E-mail:
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
Please check rates and details directly with the companies in question if you need more recent info.


1851 explored by gold miners.
07-DEC-1851 article about the exploration published by J.B. Trask in the Daily Alta California.
1919 rediscovered and explored.
1920 cave property logged as a claim.
1921 development with wooden stairs.
1922 the 33 m steel spiral staircase was build, cave opened to the public.
1924 first Moaning Cavern visitor center built.
1952 excavations by archaeologist Phil C. Orr.
1970s moaning sound restored.


The Moaning Caverns got its name because of the moaning sound that comes from wind passing over its entrance. Most people think the sound was caused by wind blowing across the cavern entrance or by cave air blowing in or out of the entrance. But actually the sound is produced by drip water holes in the sinter floor of a side passage. The water dissolved the sinter and created small bottle-like holes. The sound is created when the bottles are not full of water, and single drops falling into such a bottle produces a hollow thumping sound. Many drops create the continuous moaning sound. This circumstances are quite rare and so the moaning still exists but can be heard only rarely. The sound stopped when the spiral staircase was built during the development of the cave. The logical interpretation was that the spiral staircase disturbed the flow of the cave air. But in the 1970s the owner changed and the new owner researched the changes of the cave during the development. He found some holes which were filled with debris during the construction of the staircase. The holes were cleared of the debris and the moaning sound restored. But the development actually affected the acoustics of the cave and the sound no longer reaches the surface.

The cavern was long known to prehistoric people who held it in awe because of the moaning sound. They called it Samwel Cave. The cave was discovered again by gold miners in 1851, but they were looking for gold and when they found none they soon left. Such gold miner stories apply to most caves in the area, Calaveras County near Vallecito is located in the heart of the Californian Gold Country. But its exploration was published by J.B. Trask in the Daily Alta California on December 7, 1851. They used mining equipment, a which, a long rope, and a ore bucket to lower the explorers into the cave. And according to the description they already explored most of the cave known today. However, gold miners are no cavers and the finding was never registered anywhere, the cave and the article forgotten. So the cave was discovered a third time in 1919 and subsequently explored and developed as a show cave.

The group of people which discovered and explored the cave in 1919, bought the land in 1920. As this area is gold country and the laws for gold claims were still existing, they simply logged a claim. The side entrance existed already, but they had to use dynamite to widen it. They installed wooden stairs, later the spiral staircase, and then opened the cave to the public. Since then the ownership of the cavern has changed several times, the last time only a few years ago. The current owners renamed the cave into Moaning Caverns Adventure Park, added a zip line, renamed the tours and raised the entrance fee.

There is an old Red Indian legend telling a strange story about the cave. As it lacks any happy end or deeper meaning, we guess it is actually a true event.

Three maidens from the Miwok tribe were seeking husbands, so they went to an old and wise woman. She advised them to go into Samwel Cave and drink from the first pool. They did so, but after a week without finding a husband, they returned to the old woman. She told them to go and drink from the second pool in the cave. They returned to the cave and whilst looking for the second pool one of the maidens fell down a shaft. The Miwok tribe were afraid of caves, so nobody went to look for the girl.

Old Indian legend.

After its rediscovery in 1919, the cave was extensively explored. They found a girl's skeleton at the bottom of a drop, and as they knew the legend they told it to the Miwok tribe. So after 200 years the bones were finally returned to the tribe. Explorations have traced the cavern downward for 125 m, and explorations is still in progress.

The cave is entered down a the so-called diagonal entrance, at the side of the chamber. This entrance is artificial, it was opened using dynamite. After some regular concrete staircases a narrow wooden staircase leads to a platform 20 m below the surface. It shows a first view of the Main Chamber. Then a 30 m high steel spiral stairway leads the visitors finally down to the floor of the Main Chamber. This equals a building with 10 stories. After some time in the main chamber the tours returns to the entrance on the same way. This is the regular tourist cave tour which takes some 45 minutes. A few years ago it was simply called the Walk Tour or Traditional Tour but it has been renamed the Spiral Tour after the spiral stairway. This tour is suitable for most visitors, however you should be fit enough to descend and ascend 50 m on stairs.

The huge Main Chamber is said to be the largest single cave chamber in California. It is 55 m long and 50 m high, but the ceiling to the surface is only between 6 and 10 m thick. The guides tell that it is large enough to hold the Statue of Liberty. Like always such Explainguide talk is swallowed by visitors breathless, despite its weirdness. The Statue of Liberty (only the statue, not the pedestal) is 46 m high and would fit into the chamber. However, most people actually remember the statue as seen from its surroundings, which includes the pedestal, and the pedestal has about the same height as the statue. So this comparison is actually not very helpful, it gives the wrong expression. And actually this psychological trick is not necessary at all, as the chamber is really impressive.

The main chamber has a natural entrance, which is a 10 m deep shaft through the ceiling ending in the middle of the ceiling. To enter this way, the early explorers had to descend on ropes, through the shaft and then down the 50 m high chamber to its floor. Some years ago there was a special tour which included the 60 m rappel down the shaft and then joined the regular tour on the way out. This tour is not offered any more, there is now a zipline above ground instead.

On the floor of the main chamber archaeological excavations have revealed the remains of more than 100 humans bodies. The excavations were carried out by archaeologist Phil C. Orr from the Santa Barbara Museum of Natural History in 1952. He dated them to be about 12,000 years old, by measuring the thickness of cave sinter on the bones. Orr called this "speleological dating", a technique which was used for decades and is still common knowledge. Unfortunately, as we know today after redating using radioisotopes, it does not work. He simply measured the thickness of sinter on objects of known age and compared it to the thickness of sinter on objects he wanted to date. They were under 420mm of sinter which resulted in the 12,000 years, which made the bones the oldest human remains found in America until then. However, his method does not work, as sinter growth depends on climatic changes, and its speed changes heavily over time. And even when he published his findings in 1953 there was a lot of controversy about his results. In 1960 he tried to update his theories with C14 dating of speleothem laminae, which he argued show years like the rings of trees. He used sinter from Moaning Cavern again for his paper. This theory is not working either, as was shown when modern high resolution dating methods were used to date every layer independently. Unfortunately no one seems to have actually dated the bones using geophysical dating.

A portion of the lower parts of the cave are accessible on the so called Expedition Tours. The group is guided into the undeveloped rooms and passages below the main chamber. The trip goes through narrow passageways named the Meat Grinder, Pancake Squeeze, or Birth Canal. Finally a climb up a 10 m high chimney called Santa's Worst Nightmare leads back to the main chamber. In the more difficult vertical passages ropes are installed.

This tour is strenuous! Approximate time 2-3 hours, but the duration depends much on the abilities of the group. Participants must be at least 12 years old and be at least 1.20 m tall. We guess the size is required for some climbing parts, but they do not give more information. Minors must be accompanied by an adult. Wear clothes which are warm enough and which may get dirty, and closed shoes with traction. We recommend rubber boots or hiking shoes. You should also bring a full set of clothes including shoes to change afterwards. There are no showers, so a wash cloth and towel are recommended for a basic clean-up. Also a big plastic bag for the dirty clothes is a good idea. The caving gear is provided by the guide, including gloves, knee and elbow pads, and a helmet with headlight.