Downstream Effects of the Kilgore Project Part 4: The Snake River Plain Aquifer

If you were an old mining road up on Taylor Mountain in the Centennials, this is what the Snake River Plain would look like to you, out over the foothills, as far as the eye can see into the haze of atmosphere. PC: Alex

Love Letters Again, Still

By now, it may or may not be clear that each Part of the Downstream Effects series is a love letter that is also a sword of two edges. The first edge: a different segment of the civilian population who should be interested in not having a cyanide heap leach mine in the Western Centennials. The second edge: a different state or federal entity that should be similarly interested in preserving the purity of the Western Centennial Mountains, so as to protect their downstream charge.

Here’s a recap of Parts 1-3, as well as a Spoiler Alert for Part 4.

Part 1: Mud Lake Wildlife Management Area focused on hunters who use this state-managed wildlife area.

Part 2: Camas National Wildlife Refuge focused on birders and other wildlife viewers who visit this federally managed Refuge.

Part 3: Nez Perce National Historical Park, while being something of an outlier love-letter-wise, invited history buffs who appreciate the unique and federally recognized site at Camas Meadows.

Part 4: The Snake River Plain Aquifer is perhaps both my broadest and narrowest plea. For the sake of structural continuity, this post identifies an Idaho State Park that should want the Centennials protected, the Thousand Spring Area near Twin Falls. But the wider impact, it should become clear, is not only on all of those of us who populate the Snake River Plain, but all those who live downstream, all the way to the wide Pacific.    

An Idaho Arethusa

I remember being made aware of the mythological river Arethusa after listening to a Decemberists’ song sometime around 2003. The song is about something else, but the Greek myth of Arethusa – I found out after looking it up somewhere besides wikipedia, which, although it was launched January 15, 2001, I don’t remember being aware of it until much later – centers around a river nymph who achieved the divine ability to flow under the salty sea and pop out as fresh water on an island. 

That’s an image I’ve kept with me. A river flowing above ground, disappearing into the earth, then popping up again as the same river in a different place. 

Like a gargantuan thread that sews the landscape together. 

Sometime in 2017, when I was living in Kansas, or perhaps earlier, around 2015, when I was living in Indiana – two periods in my life best summed up as times where I got to know Idaho via Google Maps – I discovered that there has always been a creek that runs under the houses where Alex and I grew up. Our Arethusa is Crow Creek.

And now, Idaho proves itself again to be at least one level deeper than I expected her to be. Turns out that Crow Creek has her own Arethusa. The whole of the Snake River Plain does. The Snake River Plain Aquifer.

A handy, if somewhat busy, diagram showing the major sinks and flow of the Eastern Snake River Plain Aquifer. Photo from Link and Phoenix, 1996. See Digital Geology of Idaho for citation.

The Snake River Plain On The Map

In 2017, before I went to Kansas, I drove with a Spanish woman from Craters of the Moon National Monument to Idaho Falls. I am neither joking nor attempting to downplay her experience when I say that the copy-and-paste vastness of the sagebrush sea caused her to physically shrink into herself in something like an anxiety attack.

She’d never seen such flat distance and thinness of air. And neither have I. Her mind didn’t know what to do with such a sight. And neither does mine.

In this same spirit, I wish I had the heft to propose that the whole Snake River Plain (SNP) be a National Park. Or a Wilderness Area. Or a Wildlife Refuge. Or a State Park. Something protected and admired.

Let me try to convince you. Open up Google Earth. Put your cursor into the Search bar and type Idaho Falls, or Twin Falls, or American Falls, or Shoshone Falls, or Swan Falls. Switch to Satellite View, then zoom out a bit. Bring the American West into your browser window. 

Or actually, don’t bother. Here’s a screenshot. 

Google Earth screenshot. The Snake River Plain is a giant, smooth smile across the Southern Idaho.

You’ll notice that the SNP – we can call it the snip in preparation for a punchline in a few paragraphs – is essentially a giant, smooth smile that unites the mountainous Basin and Range geography to the south and the extensively glaciated ranges of the Northern Rockies. 

The SNP is a transition zone. A threshold. 

The Snake River Plain In The Landscape

It is also a record carved into the face of the earth, like the Basque arborglyphs that scraped into many trunks of some aspen stands around the northern Great Basin. 

It is the scar in the landscape formed by the southwestern movement of the North American tectonic plate over the stationary Yellowstone Hot Spot in the earth’s mantle. Every 600,000 years or so, for reasons I do not understand but grew up inside the evidence of, the Yellowstone Supervolcano blows, razing the mountains that have grown on top of it. 

The SNP is the wake of Yellowstone’s eruptions.

It may also be a prediction. A splitting. A snipping

As William J. Fritz and Robert C. Thomas say in Roadside Geology of Yellowstone Country: 

Eventually, such a hot spot might weaken the continental crust and split the continent in two. Could the track of the Yellowstone hot spot represent the start of such a break up of the North American Plate? Only time – and lots of it – will tell.

It seems to me that protecting Yellowstone National Park as it now stands, while ignoring the Snake River Plain, seems misguided. Or at least underwhelming.

Not only is the Snake River Plain as much Yellowstone as the current geyser basins and hot springs, but without the hundreds of miles of mountain-razed landscape of the SNP, geologists may not have figured out depth of the power underneath the geysers and calderas and tourists of Yellowstone in the first place.

Hadean Lake Erie

But it isn’t just a scar, or a testament to some power beneath itself. It is the fount of life in Southern Idaho. 

According to the page on the Snake River Plain Aquifer in the Digital Geology of Idaho, cradled inside the anxiety-inducing and beautiful Snake River Plain’s basalt flows is something at least as important as beauty: water.

Total ground-water storage in the upper 150 meters of the [Eastern Snake River Plain] aquifer is estimated at 200 to 300 million acre-feet, roughly the equivalent of Lake Erie. The aquifer drains to the Snake River and flows mainly southwest (Lindholm and others, 1987). [Visit link for citation.]

I’ve been to Lake Erie. Alex and I – carcinogenic-water-warning-signs be damned – baptized ourselves in its murky waters years ago. Of my nice memories of Toledo, Ohio, and of our swim in one of the five Great Lakes, I can say with all sincerity that the other side of the lake is not something I recall.

In other words, that lake is so vast as to hide its opposite shore behind the curvature of the earth. 

Among the just the top 150 meters of the 1,500 meter thick porous basalt there flows a Great Lake-sized subterranean river beneath the sagebrush of the Eastern Snake River Plain.

This is the water that irrigates our agriculture. It is our drinking water. 

If you’d like to see the aquifer, you’ll need to go to one of the many sinks that lead into it (please allow me to suggest Mud Lake WMA) or perhaps to Thousand Springs State Park, where the water from the aquifer erupts from the basalt along the Snake River Canyon, and finally enters the river.

In a final act of imagination today, please add a mental image of a failed earthen dam, allowing cyanide and heavy-metals-laced slurry to rush down Camas Creek, poisoning the wetlands of Camas Meadows and Camas NWR, coming to rest momentarily in Mud Lake WMA before sinking into the aquifer. Which all of us Southern Idahoans depend on. 

Actually don’t bother, here’s a photo from an identical incident in 2014 in British Columbia.

A Familiar Plea, Again

Let’s keep the Western Centennials and the Eastern Snake River Plain Aquifer free from a similar hellish fate. Please visit Idaho Conservation League’s convenient site where you can easily make a comment to the Caribou-Targhee National Forest against the Kilgore Project. Comments will be accepted until February 11, 2021.

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