Geology Determines Destiny
August 21, 2026
Draft 10.0

I remember as a youngster seeing a bumper sticker that sent me to the encyclopedia—"Idaho, Home of the Batholith.” I expected to find some new species of frightful monster. Imagine my surprise when I was greeted instead by a picture of a large, half-buried rock.

A batholith, as I was soon to learn, is a mass of rock formed when magma rises into the earth’s crust but doesn’t quite make it to the surface. It cools underground and may remain hidden for millions of years until erosion finally strips away enough earth to reveal it. If someone had told me then that I would spend a good part of my life hiking around batholiths, I’m pretty sure I wouldn’t have believed them.

I never took a geology course in high school or college. At the time, I never wanted to. It takes a special kind of person to wallow in schist and detrital, xenocryst and gneiss. And why such off-putting words? Were geologists deliberately trying to chase the rest of us away? The subject would have appealed to me much earlier if I had understood that geology isn’t really about memorizing strange-sounding rocks. It’s about landscapes, time, and civilizations shaped by the ground beneath them.

Much later, I came across the German geologist Hans Cloos, who wrote that stones begin to speak when there is an ear to hear them. He called geology the music of the earth. What a great teacher he must have been. The American writer John McPhee made a career of writing beautifully about geology. He once said he could reduce it all to one sentence: “The summit of Mount Everest is marine limestone.”

He could just as easily have been writing about the summit of Idaho’s highest mountain, Mount Borah. That single fact requires a little imagination. An ocean floor became the top of a mountain. Once you begin thinking that way, Idaho gets interesting in a hurry. You don’t have to travel far to realize that something momentous happened here. Seashells on the summit of Borah. A waterfall higher than Niagara. An underground aquifer comparable in size to Lake Erie that reveals itself at magical Thousand Springs. Two of the world’s largest floods known to geologists inundated northern and southern Idaho. The “hot spot” that left a trail of volcanic destruction across the Snake River Plain now sits beneath neighboring Yellowstone National Park. And that’s just scratching the surface.

In Idaho, geology affected where people settled, mined, farmed, and built roads, where some towns prospered and others disappeared. It also underpinned a surprising number of our nearly 300 Outdoor Idaho programs, with titles like “A Sawtooth Celebration,” “Land of the Lost River Range,” “A City Made of Stone,” “Beyond the White Clouds,” “Idaho’s Inland Seas,” “Fifty Years of Wilderness,” “Pend Oreille Country,” “Under Idaho,” “Mining Idaho,” “Rock Hounds,” “Gems and Geology,” “Idaho’s Middle Earth,” “Canyonlands Calling,” and “Idaho’s 12ers.”  Whenever we could, we linked a story we were telling to the land beneath it.

I knew one day I would have to face my fears and devote an entire hour-long program to the topic I once dreaded. The result was “Idaho Geology: A Convergence of Wonders.” If there were ever an Outdoor Idaho program vying for “Most Complex,” this would be in the top two or three. As I saw it, our challenge was to produce an hour-long program about geology that would appeal to Joe Sixpack without getting panned by Professor Hans Geologist. Good luck with that!

Several years earlier the station had found enough money to rent a helicopter and pilot for a program we called Idaho: An Aerial Tapestry. That aerial footage proved especially useful when we started our deep dive into Idaho’s geology. From the air, the Snake River Plain suddenly made sense. Faults appeared. Mountain ranges lined up. Lava fields that seemed chaotic from the ground revealed patterns. 

Back on the ground we tracked down footage of the Teton Dam collapsing in 1976, Mount St. Helens erupting in 1980, and the aftermath of the Borah earthquake in 1983. We also gathered remarkable footage of places only a handful of people have ever seen. My personal favorite was Blue Heart Springs, along the Snake River near Hagerman. Accessible only by boat or kayak, the 58-degree water percolating up from the bottom of the 30-foot-deep cove is visual proof not only of the Snake River Plain Aquifer, but also the power of the Bonneville flood.

The brother of our chief engineer owned scuba gear and an underwater camera. He was only too happy to help us capture closeups of the crystal-clear bubbling water. He put his hand into the sand and encountered no resistance, as if it were a false bottom. The water has traveled 100 miles underground through layers of basalt rock for maybe 150 years to arrive at Blue Heart Springs, a sapphire, heart-shaped delight that’s as pure as any water in the world.

A massive whirlpool from the great flood had gouged down into the canyon walls and intersected the aquifer, leaving the small pool. It’s doubtful early pioneers came across this sanctuary of year-round blue, but they certainly experienced and wrote about the exhilaration of coming upon nearby Thousand Springs.

Every major geological idea had to have pictures and video that complemented the words. Otherwise we knew what would happen. The viewer would go to the refrigerator. In addition to the 30 half-hour tapes we shot specifically for the program, editor Pat Metzler went through dozens and dozens of videotapes in our archives looking for video and pictures to make the science understandable. I knew we couldn’t leave the storytelling entirely to geologists. Many geologists speak in perplexingly complex paragraphs that require time to digest, and television isn’t generous with time. We needed a hook to draw in people who weren’t sure they cared. I counted myself among them, so I relied upon my own short attention span to determine where we might lose the audience.

Instead of simply showing rocks, we showed people enjoying what the rocks had created. We followed skiers to the backside of Bruneau Dunes and watched them ski down North America’s tallest single-structured sand dune. We hiked into a section of remote Succor Creek in Owyhee Canyonlands with expert kayakers in search of Class IV and V rapids. Their highly technical moves were possible because the giant boulders were slippery, polished rhyolite from volcanic eruptions. At City of Rocks, world-class climbers introduced us to granite in a way no geology textbook ever could.

During spring runoff we went to Class IV Lochsa Falls on the Lochsa River in north central Idaho. The massive V-wave could stop a boat dead in its tracks. Every third raft flipped. No one died because below the rapid a calmer stretch of water allowed rafters to collect themselves and their coolers.

We still needed teachers. Geologist Bill Bonnichsen and volcanologist Martha “Marty” Godchaux were a husband-and-wife team at the University of Idaho. A key to any television program is finding experts who can speak with authority in plain English. Bill and Marty could do that, with ease. We promised them eternal youthfulness, much like Lawrence Welk. They were happy to join us for the teaching opportunity. Marty and Bill became our kindly aunt and uncle, patiently answering silly questions in words we could understand.

Videographer Hank Nystrom and I drove them around the state—to the Sawtooths, the Lost River Range, Craters of the Moon, and other places where the landscape could serve as their blackboard. After a couple of days, Marty made a discovery of her own. “We had no idea how much work went into an Outdoor Idaho program!” she told us. “We have an entirely new appreciation of what it takes to make television.”

The feeling was mutual. We had an entirely new appreciation for Bill and Marty. They could take subjects that ordinarily sent me looking for the nearest exit and make them understandable and, even better, interesting. I only wish we could have spent a week with them. Part of their appeal was that neither seemed to have lost the curiosity that drew them to geology in the first place. At Craters of the Moon, I asked Bill why children seemed so fascinated with the place. “Most of the world’s dinosaur experts are somewhere between five and seven years old,” he said.

That was Bill. Funny with a point behind it. Kids love dinosaurs. They love volcanoes. They draw pictures of red blobs beneath the earth, lava pouring across the landscape, mountains exploding. Bill had watched them do it. Some children, he said, drew simple lava flows. Others already understood that volcanic activity could be explosive.

“I think if we had all that information available to children, they would have even greater ideas,” he said, “because, let’s face it, kids have really wonderful imaginations.” I suggested that perhaps a geologist needed a good imagination, too. Bill agreed. “We’re all drawn toward interesting and slightly wacky sounding ideas,” he said, “but they often turn out to be true.”  That may be one of the things I most liked about Bill and Marty. They knew a great deal, but they also knew how much remained unknown.

Of all the places we visited with them, they seemed particularly at home at Craters of the Moon National Monument, 750,000 acres of craggy black volcanic rock in central Idaho. The landscape contains a 52-mile-long crack in the earth known as the Great Rift, surrounded by lava flows, vents, cinder cones, and other reminders that the ground beneath Idaho has not always behaved itself. Marty saw something more. “These rocks are an inspiration in themselves,” she said. She looked across the lava and described pieces of collapsed volcanic material as “great stately ships sailing down a river of lava.” That’s not the kind of sentence I expected from a geologist.

For years I figured Craters of the Moon had the best chance of becoming Idaho’s first national park. Much of the infrastructure was already there, and the National Park Service already managed it. Supporters argued that a change in designation would bring additional tourists to small rural towns like Arco and Carey. Besides, I wondered, what damage could another hundred thousand visitors do to a black rock pile in the heat of summer?

A serious proposal eventually gained support, but the Idaho Farm Bureau and others worried that national-park status might bring new federal restrictions, including possible problems for trucks hauling hay on nearby highways. The proposal went nowhere, Idaho remains the only western state without a national park, and that seemed fine to plenty of Idahoans.

Bill and Marty were interested in something more immediate. Craters of the Moon could erupt again. Its recent eruptions have occurred about every 2,000 years, and it’s more than 2,000 years since the last one. Marty could barely conceal her enthusiasm. “We geologists, those of us who consider ourselves volcanologists, are just waiting and hoping that maybe, maybe in our lifetimes this area will see another basaltic eruption. “It’s not a given, but we’re hoping.”

Only a volcanologist could say that with such cheerfulness. If it happened, Marty said, people would see fire fountains, lava flows, and perhaps enough activity to build a few new mountains of cinder cones. She was pretty sure there would be no pyroclastic explosion of lava. “It would be the kind of thing that scientists will love to study and tourists will love to photograph.” A tourist-friendly eruption. I loved the phrase. It also told you something about Marty.

Bill was especially good at helping me understand the Snake River Plain, that giant smiley face looping across southern Idaho. Bill had written several books and a paper on the geology of southern Idaho entitled “The Bruneau-Jarbidge Eruptive Center.” He was an expert on an area of Idaho that had undergone several major scientific rewrites just in the previous 50 years.

Deep beneath Yellowstone is an extraordinary source of heat. Over millions of years the North American plate has moved across that source at roughly twice the speed of fingernail growth, leaving behind a trail of volcanic centers extending across southern Idaho. Think of a blowtorch held more or less in place while a board moves slowly over the flame. The board gets scorched in a line. On a map, you can trace that line across Idaho to Yellowstone. The hotspot isn’t moving. The land above it is. The remarkable geological feature appeared around 17 million years ago near the borders of Oregon, Nevada, and Idaho. Bill blamed tectonic plates crashing into each other over millions of years. I then offered Bill a theory I liked even better.

What if a gigantic meteorite had smashed into the earth near the Idaho-Oregon-Nevada border millions of years ago and somehow started the whole thing? It had elegance. Drama. Dinosaurs. It explained everything. Bill listened. Then Professor Bill rendered his verdict: “Forget about the meteorite.” That hurt. He explained that an impact large enough to do what I wanted it to do should have left specific evidence behind, a debris field, unusual melted products, other fingerprints of a massive collision. They weren’t there. The idea, Bill said, had gone into “the dustbin of interesting geologic ideas.”

“But it’s so simple,” I protested. “It explains so much.”
“Right,” he said, “but it doesn’t explain what is actually there.” That was Professor Bill. Imagination mattered. Evidence mattered more. I’m still holding out for the meteorite theory.

Working on the program showed me how many things we casually call facts are really our best current explanations, always subject to whatever the rocks reveal next. Plate tectonics itself was once considered a strange idea. So was the notion that a meteorite impact helped end the age of dinosaurs. Geology teaches humility. It’s a science where empirical evidence rules the day, not parables or hearsay or something on TikTok. You don’t get to vote on it. If we did, I’d vote to change the names of some of those rock types. 

Geology encourages curiosity. You have to imagine oceans where mountains now stand, molten rock where forests grow. You have to imagine Idaho as ocean-front property, now attached to pieces of land that once existed far out in the Pacific, reeled in and docked onto Idaho. And then you have to go look for the evidence. Maybe that was why Bill’s comment about children stayed with me. A five-year-old can look at Craters of the Moon and imagine the earth opening up. A geologist spends a lifetime figuring out whether the child might be right.

Here are some other things I learned just hanging with Bill and Marty. Hells Canyon did not become deep simply because the Snake River patiently cut downward. Tectonic uplift played a major role, and the Snake itself may have been late to the party. Some evidence suggests the drainage in that region once moved in a different direction. Bill pointed out that tributaries in southern Hells Canyon still reveal pieces of that older story. “The whole thing was going to the south,” he said. Now it flows north. Some geologists think the Salmon River may once have been the dominant river, with a much smaller Snake River as its tributary, instead of vice versa, as it is now.

“The Snake River is a collage of many tributary parts, of numerous pre-existing rivers,” explained Bill, “and it’s been integrated only in the last few hundred thousand years into its present form.”  I guess you could teach an entire geology class just on the changes of direction of Idaho’s two major rivers. Look at the Salmon River on a map flow north, south, east, and west. It faced a lot of geologic challenges, like lava flows, to get where it wanted to go.

Then there is the Basin and Range Province. When you look at a map, on the eastern side of the state near Arco, Mackay, and Challis, you will see long, flat valleys bordered by parallel mountain ranges. The earth’s crust there is being pulled apart. Blocks of crust drop while adjacent blocks tilt upward, creating mountains such as the Lost River Range. That stretching also creates earthquakes. Marty reduced the physics to one memorable line: “Rocks can be stretched, but every rock has its breaking point, and when it breaks, that’s when you have an earthquake.” Challis and Mackay learned that on the morning of October 28, 1983.

The Sawtooths offer another exercise in imagination. The granite we see today once cooled miles beneath the earth. Before the mountains could take the form we recognize, an almost incomprehensible amount of material above them had to be eroded away, shifted aside, worn down by water, wind, ice and gravity. “Either part of it just physically slides off, or part of it erodes away,” Bill explained. “In the case of central Idaho, both processes have occurred.” Only then could glaciers and wind and rain sculpt what we see today. The mountain range we regard as timeless is actually the exposed remnant of an enormous process still underway.

Marty had a way of making all that time feel almost accessible. “This is a fabulous state for a geologist to work in,” she told us. “I can’t think of another state that has anything better than we have here. Without having to walk very far, you can go from two billion years ago to today.” That may be the best tourism slogan Idaho never used.

Two of my favorite oddities in Idaho geology involve water. At the end of the Ice Age, Utah drained into Idaho, literally. Massive Lake Bonneville had backed up nearly a thousand feet above the current level of the Great Salt Lake. When it ruptured at Red Rock Pass southeast of Pocatello, a 400-foot-deep wall of water tore through the Portneuf Narrows.

Shoshone Falls, one of the great spectacles of North America, is the direct result of the flood. It’s not the product of thousands of years, but of several weeks! The floodwaters surged through the Snake River canyon, tearing through 600 feet of basalt and soil until it hit hard rhyolite, which acted like a dam, creating a plunge pool and thus the waterfall. Today, at 212 feet, the “Niagara of the West” is 45 feet taller than Niagara and spans roughly 900 feet across. The flow of Shoshone Falls in the spring of 2011 ranked as one of the best in recent memory.  Multiply that by a thousand, and you begin to understand the cataclysmic effect of the Bonneville Flood that hit southern Idaho.

It must have been an amazing sound of boulders the size of cabins ripped from the canyon walls, bumping and grinding along the river bottom, carried along by the incredible force of the flood. Some of the boulders of basalt bounced along the bottom for 6 miles. “One of the interesting things you find are great big sandbars,” said Bill, “but they’re really boulder bars, made out of rounded boulders, as much as ten feet across.”

At the same time, something even more extraordinary was occurring in what is now Idaho’s panhandle. A series of giant floods repeatedly tore across northern Idaho. A 2,000-foot-high and 20-miles-wide ice dam blocked the Clark Fork River near the Idaho-Montana border, creating a lake that stretched eastward 200 miles into present-day Montana. As large as Lake Erie or Ontario, geologists call it Glacial Lake Missoula. When the dam broke, the flow was 60 times that of the Amazon River and had the power of ten times the combined flow of all the rivers in the world, with speeds up to 80 miles per hour. All that water drained in 48 hours, and not just once. Most geologists believe the dam failed at least 25 times, starting                                                                                                                                                               18,000 years ago until about 14,000 years ago. And each time the flows scoured Lake Pend Oreille, Idaho’s largest and deepest lake.

On my wall, a bumper sticker urges “Restore Glacial Lake Missoula.” Tongue in cheek, of course. I can't imagine the damage done today by what one geologist called "the largest flood documented by scientists," tearing through Northern Idaho and Washington, all the way to the Pacific Ocean.

 

If you think Idaho is desert and potatoes, visit the Palouse, near the university town of Moscow, Idaho. We did and were so impressed that we devoted an entire program in 2006 to “Palouse Country.” The Palouse is some of the most productive agricultural land in the world. Farmers don’t have to worry about irrigation because the soil holds its water. The region’s winter and spring wheat is in great demand in Japan and other parts of Asia.

In Greek mythology, Aeolus is the ruler of the wind, a figure of both protection and peril, especially after the Ice Age ended about 13,000 years ago. The glaciers had ground up the basalt into something geologists call “glacial flour.” In the following climate change, lakes and swamps and gullies dried up, and massive dust storms from the west carpeted the hard lava flows with a luxurious blanket of glacial flour. Bill commented to me off camera that the wind may be the single most important reason for the soils of Idaho.

In the extravagantly plush rolling hills of the Palouse, Aeolus worked overtime. When you first see it, it’s easy to believe that the rich soil has been there for eons. Nope. Just thousands of years, which is nothing in geologic time. In some places this “aeolian” soil blew in 30 feet deep. Marty called it “the last act of the geologic drama that produced the Palouse.” The fine material left by the great floods picked up by prevailing winds and blown eastward eventually produced the rich soil that supports the region’s agriculture.

The 1983 Borah earthquake offered a more recent reminder that geology is not merely ancient history. Historian Will Durant is credited with one of my favorite observations: “Civilization exists by geological consent, subject to change without notice.” The Borah quake supplied the notice. The earthquake tore open a long rupture along the Lost River Range. Mountains and valleys shifted. Underground plumbing changed. Some wells dried up while others suddenly produced more water. Hunters near the epicenter near Mt. Borah described the ground rolling beneath them, trees whipping back and forth, and boulders crashing down slopes. One said it looked as though someone had taken scissors to a sheet of paper and cut the earth open.

My experience was considerably less heroic. It was my birthday, and I was at my cabin outside Idaho City, submerged in my sunken bathtub when the earthquake struck. I didn’t fully appreciate what had happened until I stepped into the living room and saw my stained-glass pieces swinging violently from their chains.

The earth had convulsed. There is a line from Ralph Waldo Emerson that I’ve always liked: “We learn geology the morning after the earthquake.” Earthquakes suddenly expose the forces that otherwise remain easy to ignore. Marty’s “breaking point” is no longer theory when the floor is moving beneath your feet.

There was tragedy that morning. Two young children walking to school in Challis were killed by falling bricks. Buildings in Mackay were heavily damaged. Bill and Marty could not have predicted when such an earthquake would happen. They knew where it could happen and they knew it would happen again. Marty was convinced that “There will be more earthquakes like the 1983 earthquake that will raise the Lost River Range slightly higher and drop the valley floor slightly more. It’s one more tiny installment in building the Lost River Range.”

 

The Teton Dam gave Idaho an even harsher lesson. When the dam failed in 1976, the reservoir behind it was nearly full. Billions of gallons of water rushed through eastern Idaho, destroying communities, roads, bridges, livestock, and homes. Video from the disaster is almost surreal. Houses float downstream. Trees become battering rams. Entire neighborhoods disappear beneath brown water. Because the dam failed during daylight and warnings reached many communities, thousands of people made it to higher ground. Eleven people died. The toll could have been vastly greater.

Investigators later concluded that the dam had been built in a place where fractured and porous volcanic rock created serious problems for its foundation. Engineers had tried to compensate, but the rocks got the final vote. That may be the simplest explanation of the entire disaster. The foundation built partly on political confidence and engineering certainty could not overcome the geology beneath it.

We’ve seen geology reshape landscapes and destroy people and things. It can also move a capital city. When the Idaho batholith cooled underground, mineral-rich fluids moved through cracks in the rock, leaving veins of gold and other valuable minerals. That geology helped launch the rush to northern Idaho in 1860. Lewiston grew quickly at the confluence of the Clearwater and Snake rivers and had every reason to believe it should remain the political center of the new Idaho Territory. In fact, it was the capital of the Idaho Territory for nearly two years.

Most towns relying on gold tend to lose their luster after about two years. Right on cue, rich placer deposits near Idaho City beckoned to the residents of the tent town of Lewiston. Almost overnight, Idaho’s first capital city lost most of its residents as they rushed to chase the yellow stuff 250 miles south of Lewiston. By 1863 Idaho City, in what’s known as the Boise Basin, boasted a population of nearly 10,000 residents. The “Queen of the Gold Camps” was the largest town in the northwest, larger even than Portland, Oregon. The population center of the territory quickly shifted south with the miners.

Some Lewiston residents still talk about what followed. When the territorial legislature voted in 1864 to move the capital to Boise, Lewiston officials resisted. They locked away the territorial seal and posted armed guards. Federal troops eventually helped retrieve it. To some in northern Idaho, Boise stole the capital. They call it “The Lewiston Capital Heist.” Folks in Lewiston are proud of their history. Today there is even a replica of the capital building with a sign that declares: Welcome to Historic Lewiston, Idaho—Idaho’s First Territorial Capital. The folks in Lewiston have long memories.

Perhaps Boise had an accomplice in the batholith. Gold had appeared in one place rather than another. People followed it. Political power followed the people. Moving a population base hundreds of miles in only a few months is not easy, but gold has unique power over a man and over a state. Seems like geology really can determine destiny.

 

 

 

 

 

 

 

Thus far, we have not used bold within text. We use regular, italic, and a larger bold font for chapter titles. This gives you the recommended maximum of 3 font styles on a page.

 

 

That’s a pretty great sentence.

 

 

In the world? In North America?

 

 

Very clever

 

 

oK, this is a good pull quote. I’ll start a cache for those.