Once Upon an Ice Age

I remember the geology professor pausing in his lecture on the Ice Age and sighing wearily, like he had said the words a thousand times and was getting sick of it.

“I do not like the word RETREAT,” he said. “The glaciers did not RETREAT. They did not advance down in one direction, then turn around and march back in the other direction. They MELTED. The ice MELTED and the water DRAINED AWAY.”

Of course, this was well before the days of Global Climate Change, so perhaps our freshman class was not as savvy about things like melting ice. Still, the terminology makes a subtle but important difference. Water has shaped this planet in amazing ways, and it shouldn’t get short shrift. Especially when you consider the massive volume of water that was released when those towering Ice Age glaciers began to melt. In some cases—particularly in the Pacific Northwest—it made for some real drama: the Ice Age Floods.


The Ice Age Flood of Lake Bonneville

Lake Bonneville was an ancient Ice Age lake so big it covered almost half of Utah. (Today, the Great Salt Lake is a remnant of Lake Bonneville—a tiny puddle compared to its former self.) Lake Bonneville was a pluvial lake—in a landlocked basin fed by the heavy rains of the wet, cool climate of the Ice Age. On the northern side, Lake Bonnevile was walled in by a rocky ridge – a natural dam. In one place, today called Red Rock Pass, it was slowly eroding, the rocks giving way to the softer sands below.

Then, one day around 14,500 years ago…the dam broke.

Imagine…If you had been standing on the canyon rim at Swan Falls Idaho, above the Snake River, which today looks like this…


A watercolor I did that shows the present-day view from the canyon rim.



…you would have seen something like this…


There were people in the Snake River area back then – perhaps someone actually witnessed this…?



A 300-foot wall of water shooting down the canyon!

The force of the flow was so great, it ripped out chunks of the canyon walls and sent them hurtling downstream. Today, this is affectionately known as “melon gravel”. Here I am standing by one particularly large piece of melon gravel:


Several months ago, I was asked by my clients at Idaho Power to design a sign telling this story. Swan Falls is the site of one of their dams, and there is an interpretive kiosk that tells the story of the flood, as well as the history of the power plant and the Native Americans that once occupied the canyon in winter villages.

Here is the finalized design for the Flood Sign:

DDahnSwanFalls [Converted]



If you’re ever in the Boise area, take a drive out to Swan Falls and check it out. It’s well worth the hour drive, and if you like historic power plants, you can arrange for a tour of the very cool old plant, too.

Plus, the interpretive signs (installation due in 2014) are going to be pretty great.




Add your thoughts:

What do you think! Have you ever been to Swan Falls, or another site in the Snake River Canyon? Have you ever heard of the Ice Age Floods?


Learn More:


Read a short article and watch a cool slide-show

Read a longer, more in-depth article on Lake Bonneville and implications for climate change research

Visit the Ice Age Floods Institute

Check out one of my other posts about flowing water, including a section on the Missoula Floods


Like Water for Martians

When I fly, I like to have the window seat. As an artist, I have a passion for the shapes and patterns that make up our world, and there’s no better place to observe than from the sky. It’s a landscape largely defined by the flow of water. Water has sculpted a beautiful world for us to live in.

This is an illustration I did for my Tumalo Creek project, showing the Deschutes River Watershed. The view is to the west, with the Mt. Hood and the Columbia River on the right.


When Google Earth first came out, I used to spend hours “flying” around the planet, simply enjoying the way the earth looks. I’m a geography geek at heart.

And, when Google Earth came out with their amazing “explore Mars” option, I was in hog-heaven. I could zoom through canyons and explore craters, and what had been abstract—a distant planet I knew little about—suddenly seemed almost as real as if I were there myself.

Recently, there has been some exciting news from NASA. The rover Curiosity has found  what appears to be an ancient stream bed—proof of water on Mars. It has long been suspected that water was present on the red planet, either now or in the past, but now they are sure of it. It is good news, because is means that Mars is, or was, capable of supporting life as we know it. It’s a step forward in answering one of the most intriguing questions of humankind: are we alone?

Image Credit: NASA/JPL/Texas A&M/Cornell


I find it amazing that we are able to enjoy images such as this…an actual photo of a Martian sunset, taken in 2005 by the rover Spirit. Has any form of Martian life ever seen this view? Personally, I can’t wait to find out what Curiosity digs up. Could there be fossils? Actual microbes? Tracks?

Okay…now my imagination is running wild.

Image Credit: NASA/JPL-Caltech/University of Arizona


The above photo is a composite image of the Gales Crater, where Curiosity is now. If you haven’t already tried it, try exploring Mars with Google Earth. Just go to the “View” menu, and choose “Explore Mars”. When the planet appears, type in “Gales Crater” in the “fly to” box. Another place I like to explore is the Valles Marineris—a huge canyon much longer than Earth’s Grand Canyon. It’s pretty cool.


Coming back to Earth

I few years ago, I designed, illustrated and wrote a series of interpretive signs for the Oregon Parks and Recreation Department at Hat Rock State Park. The park itself is not what you would call spectacular, but for interpretive topics, it is fascinating. Not only did it feature prominently in the Lewis and Clark expedition, but it has interesting geology, and especially interesting to me, it was a good place to tell the story of the Ice Age Floods.

This was one of a series of signs I did for my Hat Rock project.


The story of the Floods is complex, and on the sign itself, I had to be extremely brief. So, I picked one aspect of the story I thought was most interesting. As you stand on the bluff at Hat Rock, you are looking directly at the place where a cataclysmic event happened at least once (and probably many times)…and it is possible it was witnessed by human eyes.

This is how I told the story on the sign:

Toward the end of the Ice Age, about 15,000 thousand years ago, there was an enormous lake in Montana that was formed when the Clark River was blocked by a large wall of ice – an ice dam. As the ice began to melt, it suddenly broke apart and the water burst forth in one mad rush. A towering wall of water, hundreds of feet high, thundered across the landscape, spreading out over eastern Washington.

The frenzied flow was slowed by the Wallula Gap, a narrow spot on the horizon to the east of where you are now. Here, the water backed up into an enormous lake behind the Gap. The Wallula Gap acted like a nozzle on a garden hose, forcing the water through at tremendous pressure and continuing for several weeks. The water scoured the landscape, carving out huge boulders from the rocky landscape and hurtling them downriver. From where you now stand, the river would have looked chaotic. Eventually, the water would have risen over your head!

This is the view from Hat Rock, where the visitor stands as they read the sign.



The flow of water would have been unimaginably intense. If there had been people around at the time, they probably ran for their lives…probably unsuccessfully.

There are lots more stories to tell about water on earth, about physical geography, the Ice Age Floods, and hopefully, lots more stories to come from Mars. Stay tuned to this blog!

For more information on the Ice Age Floods:



To watch an awesome video animation of the Curiosity landing on Mars: