Cave Guides
Ultimate Guide to Mercer Caverns, California (Tours, Pricing, History, Map)

Ultimate Guide to Mercer Caverns, California (Tours, Pricing, History, Map)

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Mercer Caverns is one of the half dozen or so accessible caves in California. Just 5 miles outside the town of Murphy’s, the Mercer Caverns is one of the better caves in California which you can explore. It has beautiful but unusual crystalline formations and is famous for the rare Aragonite flos feri.

It is also the longest continually operating commercial cavern in the state of California. There are guest books that have been signed by paying customers from September 1885 to the present. 

Mercer Caverns Cover Image
Photo Credit: Total Escape

Mercer Caverns, California 

Many experts believe that the cave has only been partially explored, but it is enough to satiate the cave lovers. It has become a significant attraction to tourists in the state. The cave is in the limestone region like all other caves in the state

History of Mercer Caverns 

The cave was initially used as a mortuary cave by the pre-historic Indian Tribe called the Yokuts. The tribe members would bring the dead bodies to the opening and roll them inside. Since the site was a sacred one, no person was ever allowed to enter. The Yokuts were hunters, and they moved camp when the game got diminished. Over the years, the entrance to the cave was filled with dirt and leaves, and it was completely lost. 

On 1st September 1885, Walter Mercer broke through the dirt and climbed down into the cave. There he came across the remains of four adults, a child, an infant, and even took a bone home as a souvenir. Mercer named the caves as New Calaveras Cave or “new skull cave” after the skeletons that he discovered within the cave. After many years the name of the cave was changed to Mercer’s Cave, and in 1946 it came to be known as Mercer Caverns. 

Shortly after the cave was discovered, Walter built a house near the entrance of the cave. In later years, admission tickets and gifts were sold out from this same building which still stands today. After building the house, Walter began to concentrate on installing stairs to make the journey into the caverns easier for the visitors. 

In 1888 Mercer suffered a terrible accident inside the cave. The injuries from this fall, together with years of crawling in damp cave climate, led to his death on 1st November 1900 at an early age of 46. After his death, the Mercer family operated the cave for 61 years before finally selling it to Sterling and Vivian Carter.

On 2nd August 1985, the Mercer Caverns was marked as a Point of Historical Interest by California. On 1st September 2010, mercer Caverns celebrated the 125th anniversary of its discovery by Walter Mercer. 

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Geological Cave Formations in Mercer Caverns 

Visitors who take a tour of the Mercer Caverns can view an amazing variety of cave formations such as stalagmites, draperies, stalactites, helictites, flowstones, columns, and soda straws. In the deepest part of the caverns, the visitors will be able to view a delicate array of aragonite crystals for which the Mercer Caverns were awarded at the Paris World Exposition. 


Mercer Caverns Blind White Isopods
Photo Credit:

The only known inhabitants of the cave are the blind white isopods. A long time back, people regularly spotted gray squirrels and Western pipistrelle bats. But after the gates were installed at the caverns to protect it from vandalism, the bats and squirrels never returned. One can find squirrels and bats on the property but not inside the caverns.

Is Mercer Caverns Haunted?

Mercer Caverns receives a lot of tourists every year, and there have been any complaints of paranormal sightings. 

How Big is Mercer Caverns?

The Mercer Caverns has a length of 3389 ft and has a depth of 192 ft. 

Mercer Caverns California
Photo Credit: Atlas Obscura

Mercer Caverns Tours

You need to buy the ticket at the small store and then head towards the cave entrance to learn about its history and start the tour. The tour lasts for 50 to 60 min, and during this time, you will get to weave in and out of the different parts of the cave. It is an active tour and not fit for people who are avers to climbing stairs. You will be witnessing loads of beautiful geological formations such as stalagmites, stalactites, and flowstones.

Next to the bottom of the cave, one will come across an area with aragonite flos-ferri which is why this cave is so famous. Aragonite flos-ferri is a type of mineral that is only found in three other caves in the US. 

The room with aragonite flos-ferri has several such formations, and it’s mind-boggling to see them from such close quarters. It is also the lowest point that you can access in the cave and, on your way out, you will have to climb a lot of stairs and learn how they used candles during this tour.

At one point, the guide will turn out all the light to let you experience the eerie darkness of the caverns. It is great to know that visitors nowadays do not have to explore the caves only with candles as there is adequate artificial lighting. The standard tour of the cave goes to a depth of 160 ft and 208 steps down.  

Tour Prices and Discounts

USD 16 for adults and USD 9 for children aged 3 to 12 years. Group rates are applicable if there are ten or more people.

Is Mercer Caverns Cold?

The caverns maintain a constant temperature of approximately 55 degrees F throughout the year, and the relative humidity is around 90%. 

What to Wear?

It is advisable that you wear comfortable non-slip walking shoes. Sandals should be avoided as

there are metal grates on some of the steps. Dressing in layers is advisable, and if you feel a little bit of chill, you can put on a light jacket to warm yourself up. 

Mercer Caverns Hours

Mercer Caverns are open from Thursday to Monday. The gates open at 9 am and shuts at 5:00 in the evening. It remains closed on Tuesdays and Wednesdays. The first tour departs at 9:30 am, and the last tour is at 5:00 pm. The caverns remain closed on Christmas Day.  


What to Do at Mercer Caverns (Beside Tours)

There are tours at Mercer Caverns, but apart from those, one can experience what it felt like to mine at the Mercer Caverns Mining Company. One can purchase different kinds of mining rough so that the guests can experience what it felt like to mine for minerals in the 1800s.

As you slowly wash away the mining rough, you will discover mineral or fossil treasures in the bag. It is a great learning activity for the kids as each bag of mining rough comes with an identification card to quickly identify the minerals or fossils you have found. Get hold of a ‘keeper’ bag so that you can take the treasures that you find in the mining rough back home with you. 

You can also visit the Caverns Visitor Center, where there are several interesting photos of the caves on the walls and a wide range of cave-related souvenirs and merchandise.  

Best Time to Visit

Mercer Caverns is open throughout the year, and one can visit it anytime at his convenience.  

How to Get to Mercer Caverns 

Mercer Caverns is located one mile from Murphy’s Town in California, off Highway 4 in Mother Lode County. If you are coming from Highway 4 eastbound, take a left turn into the Murphy’s Business District, also known as Main Street. After traveling for half a mile, look for a sign indicating the right turn from Main Street to Sheep Ranch Road. The turn can be a little difficult to spot, but there is a sign for the cave. 


Provide a safe bat habitat
Provide a safe bat habitat!

Hotels near Mercer Caverns 

Mercer Caverns is a short distance away from Murphy’s and around five miles from Angels Camp. Both Murphy’s and Angels Camp have arrangements for overnight accommodations. Reservations are recommended as both the towns get busy on summer weekends.  

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Download our FREE Mercer Caverns Guide (Unofficial) 

Visiting Mercer Caverns 

Do you need more information before visiting Mercer Caverns? Call (209) 728 – 2101 or Mercer Caverns for an information packet. 

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