a visitor with a backpack stands in a large natural tunnel filled with fallen rocks and boulders
A visitor standing in Indian Tunnel

NPS Photo

The number of documented caves within the park currently exceeds 700 and more are found each year. There are three main types of caves found here: lava tubes, fissure caves, and differential weathering caves.

Lava Tubes

The vast majority of caves found within the park are lava tubes. They formed when the outside of an active lava flow cooled and insulated the molten river of lava inside allowing it to continue to flow. In this way, lava sometimes flowed for many miles underground until the source was cut off or diverted leaving behind an empty space or cave. Indian Tunnel is an excellent example of a large lava tube. This cave is accessed from the Caves Trail. When open, a free cave permit from the visitor center or entrance booth is required to visit the caves at Craters of the Moon.

All other caves at Craters of the Moon are closed for safety reasons and to protect sensitive bat habitat.


Caving at Craters

Learn about what it takes to visit the lava tube caves at Craters of the Moon.

Learn more
a deep fissure in the ground with a large open chasm in it
Aerial view of King's Bowl.

Fissure Caves

Fissure caves are found within the deep cracks that make up the Great Rift. Some of these caves are remarkably deep, including one particular fissure that may be passable to a depth of 650 feet (200 meters) from the surface. King's Bowl is an excellent example of one of these caves, but entry is restricted due to extreme safety hazards in and around the caves.

a small cave entrance in reddish rocks on a hillside surrounded by shrubs
A small cave formed by differential weathering.

NPS Photo

Differential Weathering Caves

These caves were formed when volcanic material was hollowed out by wind, rain and frost. These caves are relatively rare and difficult to find.

Last updated: February 23, 2024

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Contact Info

Mailing Address:

Craters of the Moon National Monument and Preserve
1266 Craters Loop Road
P.O. Box 29

Arco, ID 83213


208 527-1300

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