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Volcanic Milestone

A Centennial Celebration of Craters of the Moon

Published online: Jun 03, 2024 Family Fun Guide, Road Trips Steve Smede
Viewed 592 time(s)

From the span of lifetimes to the lifetimes of civilizations, human histories are a central facet of what separates us from this planet’s other critters. We can revel in the wonders of ancient empires. We can learn from the works and the words that they left behind. On a smaller scale, we can dig through the letters and wardrobes and storage chests of our own family histories. We can find meaning and comfort in connecting the days of yore to the world around us, and even to the days to come.

But that’s just a human thing.

Looking back on the history of the land itself is a different kind of story, one not told in generations but in ages, eras and eons. We’re talking about units of deep time that most of us can barely fathom, let alone relate to.

If you’re lucky enough to call the Gem State home, some of the world’s most mesmerizing geological relics can be found all around us. One of my own undeniable favorites is Craters of the Moon. Its namesake national monument and preserve has been a tourist hot spot for generations, and now through September, it is celebrating its landmark 100th birthday.

A Landscape for the Ages

The entire lava field covers 1,100 square miles of the Eastern Snake River Plain. It is underpinned by a massive geologic feature called the Great Rift – a 52-mile long crack in the planet’s crust.

The immense pressure has resulted in an extreme stretching process of the underlying rock. Stretching leads to friction. Friction leads to heat – enough heat to turn the rock into magma.

Surface lava first rose to reshape the landscape 15,000 years ago, even though the forces that produced it go back 30 million more. The last period of activity was more recent than you might expect – just 2,100 years ago.

Considering the timing, it’s more likely than not that the region’s earliest indigenous residents – such as members of the Shoshone Bannock tribes – actually witnessed the eruptions and lava flows in action.

According to researchers with the National Park Service, more activity is likely to occur in the future. In fact, it’s already overdue. Researchers peg the seismic cycles to occur in roughly 2,000-year intervals. For some possible proof in the geological pudding, the colossal forces at work can even be traced to contemporary events, like a massive 6.9 magnitude earthquake that rattled Mount Borah in 1983.

An Island of Inhospitality

In spite of the desolation, or in some measure because of it, the other-worldly formations have been a source of fascination for natives and westward-bound settlers alike.

Chief among them was an explorer-photographer named Robert Limbert. In 1920, he spent over half a month on an 80-mile trek over its insanely inhospitable surface, naming its standout features and documenting the area on paper and in film. He was so taken with the bizarre, quasi-alien landscape that he would later pen an article about it in National Geographic magazine.

Here are craters of dormant volcanoes half a mile wide and seemingly bottomless, huge cups in which the five-story Owyhee hotel might be placed to resemble a lone sugar loaf in a huge bowl,” he wrote. “Here are strange ice caves with stalactites and ice-encrusted walls, caves that contain as much ice in the middle of August as they do in the winter."

He originally coined the vast volcanic field as the “Valley of the Moon,” but by the time his narrative hit the printed page in the spring of 1924, “Valley” was replaced in the headline with “Craters.”

The article is a fascinating read for all its observations and descriptions of the landscape, but even more telling are the more personal, experiential notes sprinkled into Limbert’s narrative.

I noticed a hole 15 feet wide and 10 feet deep, evidently caused by the cave-in of the roof of some underground passage,” he wrote. “Happening to look down, I saw a mountain sheep’s skeleton with the horns in a good state of preservation. Carelessly I laid aside my gun, camera, and canteen and jumped down. After looking the horns over, I started to climb out, and found that the farthest I could reach lacked about four feet of the top. To be frank, I had some very queer thoughts, chief of which was, ‘Will anybody ever find me or shall I, like the sheep, lie here for years?’”

Just as the Great Rift triggered a geologic process to transform the Snake River Plain, Limbert’s article became a seismic cultural event that piqued interest from scientists and fascination from the public at large.

By early summer of 1924, President Calvin Coolidge had issued a proclamation officially establishing the Craters of the Moon National Monument.

Growth & Legacy

Over the decades, the boundaries of the monument have expanded, encompassing a larger area of volcanic terrain and surrounding ecosystems. In 2000, Craters was further designated as a national preserve, providing specific environmental protections while allowing for continued recreational use and scientific research.

On a personal note, it was also about this time that I made my own pilgrimage to the area, and like so many of the preserve’s 200,000 annual visitors, I fell in love with its “weird and scenic” atmosphere from the moment I first hit the loop road.

By the time my daughters could handle the trails, I had visited the preserve over a dozen times. In the following years, we made countless return trips to marvel at the formations, wildflowers, spatter cones, collapsed domes and vast rocky expanses of welded basaltic lava. We explored the remnant caves of molten rivers, rock-hopped into fissures where allowed, and encountered a surprising number of wild animals who call the high desert home.

On weekday summer evenings when the 90-minute jaunt seemed too far, we found a similar outlet for adventure at Hell’s Half Acre, a satellite lava field only 20 miles west of Idaho Falls.

Just like at the preserve, the mind-boggling surface proved to be as surreal as it was unforgiving. Every trip to Hell’s Half Acre became a new challenge to go in further and delve deeper. Once nondescript natural features had gradually become recognizable.

Like Mr. Limbert and other explorers of yore, we felt compelled to start naming things.

We found a narrow, semi-collapsed tunnel with a V-shaped crevice ceiling, and christened it the Bat Cave.

A nearby suspended basaltic structure became the Hanging Rock. The following year the entire arch had collapsed, so we changed it to Fallen Rock.

Further into the lavascape, we found a deep fissure with its own microclimate and a damp floor thick with lichens and leafy, long-stemmed foliage. It became the Fern Factory.

I also recall a wind-battered Juniper bent into the golden-spiral arch of a ballet dancer. We called that one the Fibonacci Tree.

At one point, my daughter Gibby became so enchanted with the place that she started abbreviating her request to just, “Hey Dad, we going to Hell this weekend?” She was only 12 at the time, so I probably should have admonished her. Hard thing to do, though, when my first reaction was always a giggle. Truth is, the only problem I had with that label was how inaccurate it was.

If anything, this quiet nook of God’s green earth had become – at least for the two of us – a sort of exploratory heaven.

To our short-lived human eyes, desolate terrain can indeed seem timeless. Now at an age and condition when such adventures are few and far between, I often find myself scrolling through my old photo albums of Craters of the Moon and Hell’s Half Acre, and I’m constantly reminded of the disparity between the swift aging of the explorers and the relative permanence of the explored.

But looks can be deceiving. The big clock is not just a time-keeper for the human condition. It ticks away for everything. Just ask any unfortunate mountain sheep trapped in a crevice, or any basaltic arch collapsing under its own weight into scattered rubble, or even the Great Rift itself – shaking, slipping, stretching and sliding on a massive conveyer into oblivion and back again.

What exactly lies in the lava fields’ future is hard to say. What we can foresee with some certainty is that in the coming months, Craters of the Moon National Monument and Preserve will continue a celebration of its first 100 years. Each month has its own theme, ranging from cultural history to wilderness exploration, research, geology, night-sky photography and other topics.

The presentations and programs will surely educate and entertain, but make sure to carve out time in your visit to discover the majesty of the preserve on your own schedule. Traverse the designated trails. Take in the vistas. Read the signage. Marvel at the ancient flows and towering relics of the planet’s chaotic past. In doing so, you might find not only beauty and inspiration, but a deeper connection to the world around you.

All the details can be found at


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