Lava Tubes at Craters of the Moon National Monument, Idaho

by Nickolas Neely / Photo ©  National Park Services

Craters of the Moon National Monument and Preserve contains three different major lava fields, covering an area of roughly 1,200 square miles. Geological rifts (areas where the Earth’s crust is being literally pulled apart) dot the landscape. Early pioneers who encountered this region on their journey west referred to it as “The Devil’s Vomit,” a commentary on how they felt about having to cross it or make their way around it. In such an inhospitable environment only choice exotic plants can still survive year round. This area’s geography is so foreign that NASA used it in 1969 to prepare astronauts for trips to the moon.

Lava tubes in this brittle landscape provide the National Monument another layer of exploration: subterranean. On your hike through Craters of the Moon, be sure to explore the main four caves on the monument: Dewdrop, Indian, Boy Scout and Beauty.

Indian Tunnel, which measures more than 800 feet long, by far the longest of the lava tubes, is navigable by a series of metal stairs and earthen pathways. With 30-foot ceilings and natural skylights illuminating your path, a trek through these lava tubes is an exotic departure from your standard nature hike.

The stalactites descending from the ceiling will be different from those in an average cave. Because they were formed through lava, their colors will vary far more than normal.

The other three lava tubes, while not nearly as cavernous, are still worth visiting. You’ll need to squirm and slide to make it through the Boy Scout Cave small entry. However, Boy Scout is unique because it keeps its winter chill throughout the year, retaining ice at all times. These three caves will require you to bring your own lighting.

To enter Beauty Cave, you must scramble down some large rocks to reach the cave floor, which is a surface of pahoehoe, or lava that flowed downhill to create the surface before it solidified.

Crater of the Moon National Monument and Preserve requires visitors to acquire a permit before exploring the lava tubes. Pick one up for free at the visitor center. If you want to extend your trip into a weekend stay, the Preserve includes a number of campsites. For more information on the Craters of the Moon, go to nps.gov/crmo. To learn more about visiting Idaho, go to visitidaho.org.