How the devastation of the ice age floods shaped Spokane and still deliver its most important natural resource.

When I was at Washington State University in the late 1970s, my journalism professor, Chuck Cole, would often refer to Spokane as “Camelot.” As a salty realist who worked on the copy desk of the Spokane Daily Chronicle during the summers, Chuck said “Camelot” as though he’d just sipped a gin & tonic that was missing the gin. He did not offer it as a compliment.

I didn’t quite understand what he was getting at, at least not at first.

But what Professor Cole meant is that the ownership of Spokane’s newspapers by the preeminent Cowles family—with its civic prominence and extensive real estate investments in the city—often discouraged clear-eyed journalism about how the city actually worked, or didn’t work. Consequently, what prevailed was a sanitized version of life in the city, one frequently at odds with Spokane’s actual power dynamics and actual history. “Camelot” was just Chuck’s way of capturing it all with one breath and a priceless facial expression.

Whether the foibles, crimes, remedies and triumphs in Spokane’s past are all that different from those in the histories of other American cities is beyond my purview, at least for this exercise. But geology and human history do meet at the Spokane falls. It’s clear that the city as we know it was built upon gifts delivered by ice age floods. It’s equally clear that the city spent the first chapters of its urban history recklessly despoiling those assets. Undoing those early mistakes has, in turn, become a laudable, modern success story; one that is still underway.

The signature gorge was largely sculpted by what J Harlen Bretz began referring to as the “Spokane Flood” based upon his geologic field work in the early 1920s. Bretz wasn’t exactly sure what unloosed the inland tsunami of glacial floodwaters. But he knew, for certain, that the torrent had plowed through what is now Spokane, and spilled out, from there, to create the channeled scablands.

Spokanites, for the most part, don’t think of themselves as living in the flood-ravaged scablands. That’s likely because the city’s robe of pine forests and mountain views to the north and east don’t at all resemble our image of the scablands as treeless and parched. But the evidence of the ice age floods pulverizing visits abound. If, for example, you’ve gotten frustrated driving on the South Hill because roads suddenly terminate at duplex-sized basalt mounds, you’ve come face-to-face with the chaotic zoning legacy of Lake Missoula floodwaters. And yet the rock smashing floods also delivered what turned out to be invaluable gifts.

The first is the city’s namesake river. It’s not that the river didn’t exist before the Lake Missoula outwash floods. It did. But the geologic evidence is that it flowed well to the north of what is now downtown Spokane through what geographers call the Hillyard Trough. The loads of debris dumped into the trough by the Lake Missoula floodwaters effectively shoved the river miles to the south, thus setting the stage for the creation of the city’s signature natural feature, not just the braided falls but the gorge beyond.

Spokane was founded as the town of Spokane Falls in 1881. At inception, the city’s namesake river was an obvious resource both as a source of drinking water and a healthy fishery. Yet it was soon degraded by pollution and unbridled development.

A quarter century later Spokane’s park board commissioned the nationally prominent Olmsted Brothers to evaluate the rapidly growing city’s need for adequate park properties. In their report back, the brothers all but pleaded with city leaders to protect the scenic river gorge extending miles downstream from the falls. In their report the Olmsteds chided Spokane for the improvements (they put quotation marks around the word “improved” to register their sarcasm) that were already encroaching and diminishing this “tremendous feature of the landscape.”

The signature gorge was largely sculpted by what J Harlen Bretz referred to as the “Spokane Flood” based upon his geologic field work in the early 1920s. Bretz wasn’t exactly sure what unloosed the inland tsunami of glacial floodwaters. But he knew, for certain, that the torrent had plowed through what is now Spokane, and spilled out, from there, to create the channeled scablands.

In the century since Bretz set forth his Spokane Flood theory, geologists have found evidence that each of the cataclysmic breaches of the Lake Missoula ice dam near present-day Clark Fork, Idaho, opened the icy floodgates for approximately 500 cubic miles of water. The main pathway for the unloosed torrents was the Rathdrum Prairie to the southwest, where flood depths are estimated to have reached 700 feet, higher than two football fields stacked on end. The lion’s share of that water headed right for Spokane.

There is an important footnote to the Spokane Flood story, and I’ll place it here. Geologists are now persuaded that many, if not most, Lake Missoula flood events occurred during periods when Spokane was already under water as a result of ice lobes blocking the Columbia or the Spokane rivers. This means there would have been at least several events when the Lake Missoula floodwaters were suddenly added to existing glacial lakes that would have dramatically overflowed and sent floodwaters surging into the eastern tracts of the channeled scablands.

In the Spokane Valley, Lake Missoula floodwaters reached at height of 2,800 feet, nearly high enough to reach the 3,000 foot summit of the thumb-like “Big Rock” that is popular with elite climbers. Trying to envision floodwaters reaching the ridge below Big Rock and overflowing it is mind-bending, to say the least.

The scale of the great floods’ earthly remodeling in and around Spokane tests the imagination. One popular place to experience it is where my mom was standing when my dad took a photo of her in August of 1954. The two were in Spokane on their honeymoon and visited the “Bowl & Pitcher” on the Spokane River, three miles west of downtown.

In the photo, she stands atop a six-story-high gumdrop of Grande Ronde basalt. Above the river behind her are rock walls that climb more than 600 feet to the crest of rimrock just west of Palisades Park. The floodwaters didn’t just top the rimrock high above the river, they stormed over. One result is that the plateau landscape in Palisades Park is classic scabland terrain, with turrets of exposed basalt and just enough topsoil accrued over the past 12,000 years or so to support loose stands of pines, shrubs, and wildflowers.

Another place to challenge your imagination is at the high ridge line at the Rocks of Sharon in the Dishman Hills Natural Area in the Spokane Valley, an area that received the full force of the Lake Missoula torrents. The Rocks of Sharon consist of ancient gneiss and granite—many millions of years older than the surrounding basalt—that were crested by the floodwaters. The floodwaters reached a height of 2,800 feet, nearly high enough to reach the 3,000 foot summit of the thumb-like “Big Rock” that is popular with elite climbers. Trying to picture floodwaters reaching the ridge below Big Rock and overflowing it is a bit mind-bending, to say the least.

Down at river level, in west Spokane, another astounding glacial flood feature is hidden in plain view. These are enormous bars of gravels and cobbles deposited by the Lake Missoula floods as the floodwaters completely overwhelmed the river gorge. What disguises them is a layer of topsoil that supports grass and pines, hawthorn and willow. But just under the veneer of soil are the billions and billions of small boulders, cobbles and gravels dropped by the floods.

The boulders and cobbles are brilliantly exposed in the Spokane River, and spectacularly so at my summer swimming hole near the City’s Downriver Golf Course.

Almost all of the vast cobble pile extending fifty miles toward Sandpoint, Idaho, is now saturated with cold, naturally purified water. We know it as the Spokane Valley/Rathdrum Prairie aquifer, the City of Spokane’s sole source of drinking water.

This stretch of river—which my friends and I know as “the big eddy”—is only a mile and a half upstream from where my mom posed at the Bowl & Pitcher. Here, the river funnels in through a set of rapids and opens into an expanse a hundred meters wide before the current is split by a cobble bar that becomes an island by mid-summer. As the two streams come together again their flow then confronts a massive cobble bar, one that towers more than 100 feet above the river. It forces the river to make a right turn through another set of rapids. In this space, sometimes into early fall, I get to swim with native redband trout, northern whitefish, the occasional beavers and garter snakes, colorful crawfish, and a mostly merry parade of humans in a variety of small vessels.

The sheer mass of the Lake Missoula cobbles and boulders is astounding. As you would expect, the pile extends more than fifty miles back toward Lake Pend Oreille, near the site of the glacial ice dam that was the exit for the breakout floods. The depth of the pile is more than 500 feet at the Idaho/Washington state line east of Spokane, but the thickest portion of the pile (apparently deeper than 800 feet) appears to be in the Hillyard Trough, where the massive dump of glacial flood debris redirected the course of the Spokane River to the south, through what is now downtown Spokane and the gorge to the west.

Almost all of the vast cobble pile is now saturated. We know it as the Spokane Valley/Rathdrum Prairie aquifer, the City of Spokane’s sole source of drinking water.

There is at least a touch of serendipitous comedy to the discovery of the aquifer in 1894. A city contractor excavating at the site of what would become the city’s Upriver Dam on the Spokane River, essentially hit a gusher of fresh water while digging into the cobbles. That was timely because, even by that time, the city was well on the way to so badly polluting the Spokane River that it would become essential to find an alternative source of unpolluted drinking water. The aquifer provided that, beginning in 1908.

It would take another half century for the city to even begin (1958) to treat the raw sewage it was dumping into the river, and this was more than two decades after the state declared the river a public health hazard in 1931. Fast-forward another half century, to the present, and the City of Spokane—thanks to new generations of civic leadership and ardent environmental activism—is on the verge of completing one of the most effective waste water treatment plants in the world.

The fluid interplay between the river and the aquifer is extraordinary. As a matter of geography the Spokane River’s headwaters are at Lake Coeur d’Alene directly to the east. But from the state line westward the river goes through stretches where it discharges much of its water into the aquifer, and then, as it approaches the cities of Spokane Valley and Spokane, it goes through stretches where it receives large volumes of cold groundwater from the aquifer.

This matters most in the summer because by the time the river reaches west Spokane, its flow depends almost entirely upon inflow from the aquifer. There are hydrogeological maps that show the areas where aquifer recharges the river. One of the river recharge areas encompasses the big eddy, where I swim and where—because of the dominance of aquifer water in late summer—the river gets even colder as the air temperature in August regularly surpasses 90 degrees.

In the context of a hot summer day, the slap of cold water to the body is a wake up call, and a reminder of the ice age cataclysm that still manages to deliver cold water from Idaho.

–tjc

Next Up: Frenchman Springs Coulee