Pluto’s Cave: See the Lava Tubes of Northern California

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Beware: You should never explore wild caves alone or without proper gear. Consider getting in touch with a Grotto of the National Speleological Society at or a qualified cave club. These groups are skilled and will train you. Without sufficient knowledge, preparation, and equipment, cave exploring can lead to serious injury or death.

Pluto’s Cave is a lava tube created by the eruption of basaltic lava from a vent located approximately 8 miles northeast, between Deer Mountain and The Whaleback. Visitors can hike up to about 1200 feet into the Cave without any safety concerns.

Despite cave-ins in the initial section of the main tunnel, individuals equipped with appropriate gear and sufficient courage can travel nearly 2 miles to reach the final segment. Nevertheless, the absence of an exit necessitates navigating one’s way back to the starting point.

An image of Mount Shasta from a distance, which erupted and formed Pluto's Cave some 190,000 years ago.

History of Pluto’s Cave

Pluto’s Cave is a lava tube cave that has been there for thousands of years due to volcanic activity. An overview of Pluto’s Cave’s history is provided below:


The Shasta Valley, located on the northern side of Mount Shasta, contains a series of ancient lava tubes that are relatively unknown and less frequented by visitors. The tubes formed approximately 190,000 years ago, during the emergence of the northern parts of the Cascade Range and the eruption of Mount Shasta.

As the outer layer of the lava flow solidified, the underlying molten lava continued to flow, resulting in the eventual drainage and formation of a hollow tube.

Pluto’s Cave is a significant conduit responsible for transporting the majority of lava into the Shasta Valley. The small lava domes near the main entrance are known as pressure ridges, or schollendomes.

These domes were created when the lava tube filled with lava, resulting in increased fluid pressure. This pressure caused the lava flow to inflate, leading to its upward movement, bulging, and forming these small domes.

Discovery and Naming

The Cave gets its name after the Roman god associated with the underworld, because of its dark and enigmatic characteristics. The Cave’s discovery remains uncertain. It is presumed that Native American tribes, including the Shasta and Modoc, were likely aware of its presence before the arrival of European settlers.

Historical Significance

The Cave is culturally and historically significant to the Native American tribes in the area. It’s thought to have served indigenous communities for ceremonial, shelter, and practical purposes.

The geological formations, including the lava stalactites and stalagmites, might have possessed spiritual or religious significance for these tribes.

European Exploration

European settlers first explored Pluto’s Cave in the late 19th century. The Cave has since garnered attention from adventurers, scientists, and curious individuals fascinated by its distinctive geological characteristics.

Preservation and Recreation

Pluto’s Cave is currently under the management of the U.S. Forest Service, specifically as a component of the Shasta-Trinity National Forest. They make efforts to conserve and safeguard the Cave while facilitating visitor access to its remarkable features.

A parking area and trail facilitate access to the Cave. However, visitors must adhere to guidelines to preserve the Cave.

Visiting Pluto’s Cave

To make the most of the trip, adhere to designated paths to reduce environmental impact. With that said, let’s take a look at some of the trails and paths within the cave.

Tour Path

Exploring the cool depths of Shasta can be a perfect activity to dodge the summer heat. The temperature inside the Cave is constant at 50 degrees, irrespective of external conditions. Plotting coordinates on Google Maps and setting the direction to the north may result in an initial error.

Highway 97 branches off from Interstate 5 in the town of Weed. The route, known as the Volcanic Legacy Scenic Byway, derives its name from its path along the Cascade Range, home to numerous volcanoes. The remnants of the 2014 Boles Fire were evident along the first 10 miles of the highway.

As per Google Maps, taking a shortcut from the highway is possible. The location consists of a rural residential area. This remote residential area is not visible on Google’s Street View.

The front gates are adorned with signs that effectively discourage trespassing, making it highly unlikely for anyone to attempt to sell solar energy panels in this area.

The Sagebrush Trail

This journey will lead to a vast expanse of sagebrush, culminating in a sizable opening approximately 10 feet below the valley. The Cave is moderately deep, and the rim is extensive, strewn with sharp-edged boulders.

Upon navigating through a narrow cave opening, you will encounter the concealed entrance to Pluto’s Cave, cleverly hidden by green shrubs.

A visible light from behind propels you forward. The path will lead you to traverse rocky terrain until you reach a cave opening that permits the entrance of natural light. The floor transforms into sand, making it easier for cavers to navigate as they approach the remarkable opening.

As you venture deeper into Pluto’s Cave, sunlight gradually diminishes. As you commence towards rock climbing, you’ll find yourself enveloped in darkness, necessitating a transition to a position on all fours. It is recommended to bring a headlamp. The odor of the cave is rather pungent and persistent, but you can’t do much to escape that.

Safety Precautions for Visiting Pluto’s Cave

There is no charge or permit necessary to access the Cave. Please comply with the specified rules and regulations.

  • It is advisable to adhere to designated trails.
  • Food, drink, gum, tobacco, candy, bottles, and canteens are prohibited within the Cave.
  • Pets and animals are prohibited from entering the Cave. Refrain from leaving pets unattended in vehicles.
  • Human waste is absent within the Cave. Don’t leave any trash here.
  • The cave prohibits the presence of fires, torches, and smoking.
  • Camping within or close to Pluto’s Cave is prohibited.
  • Appreciate geological formations, animals, vegetation, and plant life while limiting collection to litter only.
  • Please exhibit proper respect towards the Cave and refrain from engaging in vandalism.
  • It is advisable to continuously engage in caving activities accompanied by at least one additional individual.
Pluto's Cave, shown from inside where sunlight illuminates one of the tunnels from a hole above.

Wear Appropriate Footwear

Wear appropriate footwear when exploring the Pluto cave due to its slippery conditions. While there are jagged rocks around outside, cooled lava can be surprisingly smooth.

Bring Flashlights

Pluto’s Cave lacks any natural illumination, necessitating the presence of multiple flashlights for adequate visibility. If you don’t come prepared, you’re going to have a hard time. You’ll receive prior notice regarding the complete darkness within the Cave. There is a significant challenge of navigating without proper lighting and the potential difficulty of exiting. Don’t take any chances.

Wear Suitable Safety Equipment

Adopt appropriate safety measures to ensure a safe and cautious exploration of Pluto’s Cave. Consider the topographical features of the location before proceeding. Also, please remember to pack warm clothing, even during the summer season. Certain sections of the Cave can reach temperatures as low as 40 degrees.

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