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

A century ago, J Harlen Bretz dazed the American geologic establishment with his answer to the mysteries of eastern Washington’s channeled scablands. We now know it was the right answer; a remarkable triumph of earth science detective work. It just wasn’t received that way at the time.

Quite the contrary. In the 1920s, and for decades to follow, the blowback from Bretz’s fellow geologists was fierce and deeply unsettling given the effort and quality of his field work. But that is how Bretz became the central figure in a story that is less about science, and more about perseverance in the wake of human folly. It has a mostly happy ending. In 1979, at the ripe old age of 96, Bretz was finally decorated with the Penrose Medal, the highest award bestowed upon American geologists. He died two years later.

I think of it as Bretzland—a still largely uninhabited archipelago of places where the story still comes to light, often in dramatic fashion, and all the more so if you know what you’re looking at.

One of the best things about the Bretz saga is that, for the most part, you can still see what he saw. It’s in the rocks, and literally beneath your feet when you walk into places like Dry Falls south of Coulee City, or Devil’s Canyon in the desert well north of Pasco. The evidence for the “Bretz floods” stretches all the way from western Montana, through north Idaho and into the lower Columbia River basin, and all the way through the Columbia River gorge.

The installment on the Drumheller Channels (below) is the second dispatch highlighting a dozen of my favorite destinations, to be updated weekly.

•Lake Creek Coulee, Lincoln County

Coffee Pot Road is just the kind of road you might expect to be on after an argument with your girlfriend or, win or lose, when you’re nursing a hangover the day after the Apple Cup. The road leaves Harrington (pop. 415), makes a slight wobble northward, and then takes a bee-line westward toward what geologists refer to as the Telford tract, the central braid of the channeled scablands.

If I’m driving, and you’ve missed your chance to escape the vehicle when we were getting gas, an hour ago, in Airway Heights, then I will alert you to how banal this looks—this un-shouldered strip of asphalt that undulates only slightly through fields of dryland wheat. In winter, with a cover of snow and hoarfrost, it looks like what I imagine treeless Siberia looks like. If you are like me and can find the beauty in bleak, this is a highway for you too. Wired into modernity, so much of our transactional and emotional energy goes into adjusting ourselves to human constructs and relationships. What a relief it can be to simply absorb earth and sky for a change, to watch a kestrel hovering before making a dive into the grass for his lunch.

Bleak quickly evaporates once Coffee Pot road reaches Lake Creek Coulee and the main branch of the Telford tract. The pavement dips and curls as it enters the coulee and, in the time it takes to miss your mother, you’re passing by a broad expanse of marsh—lush in cattails and birdsong—and looking up at a towering wall of Wanapum basalt that, in morning light, glistens with orange and yellow lichens.

There are many other dramatic transitions between soil and scabland in the lower Columbia Basin (Highway 2’s descent into Moses Coulee in Douglas County comes to mind) but few announce the life force of water as eloquently as an arrival at Lake Creek Coulee.

The catastrophic, ice age flood waters that bulldozed the coulee also opened the terrain for lakes and wetlands that would not otherwise exist. In the rain shadow of the Cascades, this section of Lincoln County receives only about a foot of precipitation annually. But with the water-absorbing topsoil rinsed away and groundwater flowing from aquifers in the exposed basalt layers there are permanent lakes and streams. (Although, it has to be noted, hydrologists now warn about the depletion of these slow-to-recharge aquifers as a result of pumping for irrigation.)

The pavement dips and curls as it enters the coulee and, in the time it takes to miss your mother, you’re passing by a broad expanse of marsh—lush in cattails and birdsong—and looking up at a towering wall of Wanapum basalt that, in morning light, glistens with orange and yellow lichens.

A signature feature of Lake Creek Coulee are several ringed, basaltic craters that are accessible on federal Bureau of Land Management tracts north and east of Odessa. Geologists surmise the circular forms of the craters were set in place roughly 15 million years ago when the Roza lava flow inundated the area and came in contact with surface waters. The finishing touches were provided when ice age floods swept off topsoil and plucked out the looser rock between the stronger dike “rings” of basalt. This gives the craters their target-like appearance when viewed from above.

I live in a city where the clatter, thump, and hum of humanity (and its pets) are omnipresent. I can imagine that going noiseless is, for some, a little frightening. But it’s worth a try.

Lake Creek Coulee is one of my favorite places to photograph lichens—the complex fungi-algae-bacterial communities that grow very well on basalt faces, especially basalt outcroppings that are at least partially shaded from direct sunlight. In Amphitheater crater, and other places, some of the basalt walls are densely coated in bright yellows and oranges, with shades of green and red. The natural paint job is surreal.

I find myself being pulled into this part of the world during winter when the roads are passable, or even if they’re not. It’s so quiet and there are so few people. I remember a day in February when I hiked through the drifting snow to the frozen twin lakes north of Coffee Pot Lake. The only sounds I heard, for hours, were from a howling and yipping pack of coyotes.

Coming from Harrington, Coffee Pot Road makes a long loop through the Telford tract, eventually emerging within sight of Amphitheater crater to join state highway 21 a few miles north of Odessa. A trailhead that opens paths to Amphitheater and other craters is just up the hill (take a right) on Highway 21, and it’s a good place to explore, especially in the spring when wildflowers abound. When the weather is warmer, you’ll want to be mindful of rattlesnakes, especially if you’re bringing dogs with you.

Next: The Drumheller Channels near Othello

•The Drumheller Channels

Splayed on regional maps, the channeled scablands resemble an enormous jellyfish. At least that’s how it looks to me, with present-day Spokane and points west at its head and the tentacles of the flood-scoured pathways generally drifting to the southwest.

“Like roads to Rome,” J Harlen Bretz wrote in 1959, “all scabland rivers led to the Pasco Basin.”

Still, some took a more circuitous route than others.

The Telford tract floodwaters that carved Lake Creek Coulee in central Lincoln County (see entry #1) were headed toward Pasco until they reached the Crab Creek valley near present-day Odessa. Confronted by highlands to the south, the riot of rocks, water and ice made a sharp right turn and followed the Crab Creek drainage to the west. It was only when the rampaging floods reached the Quincy Basin—north of present-day Moses Lake—that the swirling chaos turned southward.

To reach Pasco the floods had to pass through a bottleneck at present-day Othello. The larger, northern portion of that bottleneck is known as the Drumheller Channels.

When Bretz and his small entourage of geology students charted the Drumheller a century ago, the phalanx of basalt buttes and maze of deep, interconnecting flood pathways were awe-inspiring.

“Drumheller is the most spectacular tract of butte-and-basin scabland on the [Columbia] plateau,” he wrote. “It is an almost unbelievable labyrinth of anastamosing channels, rock basins, and small abandoned cataracts.”

The Drumheller was designated a National Natural Landmark in 1986. But it still may be the one must-see natural wonder in the state that most Washingtonians have never visited, let alone even heard about.

Apart from its place in Bretz lore, the Drumheller’s main attraction for me, as a photographer, are the flood-carved buttes on either side of Crab Creek where hundreds of towering basalt crystals form breathtaking palisades. It’s telling that when National Geographic featured the scablands in a 2017 spread, Formed by Megafloods, This Place Fooled Scientists for Decades, the centerpiece photo for the article framed one of these buttes against a backdrop of storm clouds.

From the tops of the palisades you can readily see for miles in the direction from which the floods arrived, and imagine what that must have looked and sounded like.

I learned about the Drumheller palisades several years ago while watching a short internet video featuring Central Washington University’s talented geology professor, Nick Zentner. In the midst of his on-site lecture, Nick set his rock hammer down, only to have it bounce into one of the hexagonal cracks that separate the basalt columns. This might not have mattered except Zentner was sitting on top of the columns, and the hammer fell roughly 50 feet down the crack, lost for good. Laughter ensued.

Part of what got my attention is that the tops of the long, slender columns are exposed and, from above, appear as enormous tiles—so large you can easily distinguish them in Google Earth photos taken from far above. Some of the columns are free-standing, separated from the main faces of the buttes by several feet.

The basalt in these photogenic palisades was delivered in one of the younger lava flows (approximately 10.5 million years ago) that, collectively, make up the Columbia River Basalt Group. It is known as the Elephant Mountain member of the Saddle Mountain Formation, and it flowed westward from vents near present-day Lewiston, Idaho.

While older basalt flows also form handsome palisades in the Drumheller, the exposed Elephant Mountain fronts are, in a word, stunning. Of course, the reason they’re exposed is that ice age floodwaters were funneled into the area at high velocity and depth, and what we see is the result of the soils and much of the surrounding rock being ripped open and swept away. From the tops of the Elephant Mountain palisades you can readily see for miles in the direction from which the floods arrived, and imagine what that must have looked and sounded like.

When I first approached the dramatic butte where Nick Zentner lost his rock hammer, I’d been hiking through the channels with my old friend Larry Shook for over an hour. Aside from our own voices, the only other sound we heard came from a flock of Sandhill cranes soaring above us.

The cranes speak to the main attraction of the area, which are the migratory cranes and the dozens of other species of birds and terrestrial animals, including a healthy and loud population of frogs in Crab Creek. It’s also home to my favorite summer wildflower, the Green-banded Mariposa Lilly which is uncommon but, in the Drumheller, can appear in abundance, it’s ornate, long-stemmed and ghostly lavender blossoms swaying in the warm breeze.

Although the main perimeter roads are open year around, be aware that from October until early spring much of the interior of the refuge is off limits to protect cranes and other migratory birds. To get up to date information on access you can call the refuge at (509) 488-3140. Hiking is best in early to mid-spring before cheatgrass spurs and rattlesnakes emerge along with the sometimes withering heat. I prefer the rattlesnakes to the cheatgrass, but that’s just me.

———
How to Get There

From Seattle or Spokane you’ll first want to find U.S. Highway 17, which is accessible off Interstate-90 at Moses Lake. If you’re coming from the south, on U.S. 395, you can pick up 17 near the town of Mesa. On 17, ten miles south of Moses Lake, turn west on state route 262. Before long, you’ll pass the Warden Lake RV resort on your left and begin to notice the jaw-dropping terrain that Bretz noticed a century ago.

As you approach O’Sullivan Dam from the east you’ll come to a sign directing you to the headquarters of the Columbia National Wildlife Refuge. The federally-managed refuge encompasses most of the Drumheller, or at least that part of the Drumheller that has not been submerged beneath Potholes Reservoir since 1949. My advice is to ignore the sign to the refuge and stay on route 262. Keep going westward across O’Sullivan Dam, continuing along the elevated roadway between the Drumheller on your left and the massive Potholes Reservoir on your right.

A couple miles past the dam you’ll come to H Road SE, on your left. Turn there and follow the road up the long grade on what is basically the eastern nose of the Frenchman Hills. Continue until you reach a stop sign where H Road SE comes to a “T” at 12 Road SE and McManamon Road. Turn left on McManamon. After about a mile or so you’ll see a visitors’ turnout on your left which affords the best publicly accessible overview of the Drumheller. The elevation gain gives you a superb overview of the entire Drumheller area, and it’s worth stopping at the overlook to check it out and get your bearings. From there, McManamon swings south and east, passing over Crab Creek on the way to Morgan Lake Road and the headquarters of the wildlife refuge near Othello.

Next: Northrup Canyon

•Grand Coulee & Northrup Canyon

The challenge in writing about Grand Coulee is the problem of scale—the difficulty of arranging words to describe events and scenes so over-sized they strain credulity.

That would be true even without Northrup Canyon, a stunning and somewhat hidden annex to Grand Coulee that is carved into the highlands south of Electric City.

As J Harlen Bretz came under fire from critics in the pantheon of the American geologic establishment for his provocative (and correct) great flood thesis, he would occasionally insert what amounted to throw-down arguments in the text of his papers. His first-hand witness to the scene at Grand Coulee/Northrup Canyon was one of those arguments.

“Again and again,” he wrote in 1932, “the writer has asked others and himself ‘Where is the dangerously weak point in the [great] flood hypothesis?’ One can stand on the brink of Northrup Canyon and aver with confidence that it can never be satisfactorily explained except as an extinct Niagara [Falls].”

On a late summer day a few years ago I caught a quick glimpse of the sign for Northrup Canyon as I was whizzing toward Electric City at 60 miles an hour. I drove for a mile, admiring the granitic outcrops that had suddenly come into view, and then did something I usually don’t do. I turned around, to see what I would be missing if I hadn’t turned around.

The brink of Northrup was good enough for Bretz. Broader views would come later from satellite and high altitude photography. But there’s nothing quite like the water-shaped scarps at Northrup Canyon, with their massive rounded pillars and lobes, to translate the power of the force behind its creation.

River-carved canyons, even very large canyons, are V-shaped. Because they were created in a much different fashion, Bretzland canyons are broad and U-shaped, and none more so than upper Grand Coulee, between Coulee City to the south, and Electric City to the north.

At Grand Coulee the epic floods created a pair of enormous cataracts twenty miles apart.

At Dry Falls, just south of Coulee City, it is as though the earth clock stopped at 11:55 p.m. of the Pleistocene epoch. What one sees today is basically what you would have seen 12,000 years ago, at the end of the last ice age—minus the visitor’s center and the mobile concession stand. It is the intact remains of a once-astounding waterfall, one that is commonly described as having five times the width of Niagara Falls, and more than twice as deep. Today it just lacks water, except for the slack water in the plunge pool lakes below its face.

The northern cataract—which retreated to where Electric City is today—was even larger than the one at Dry Falls. Eventually, nearly all of the cataract was swept away under the constant assault of the late Pleistocene floodwaters. What it would have looked like is left to our imaginations.

It helps that a large, orphan chunk of it survived. We know it as Steamboat Rock, a popular destination with a sprawling campground surrounded by Banks Lake, a reservoir that receives water pumped uphill from Grand Coulee dam. The route to Steamboat Rock is state route 155 which hugs the east side of the coulee between Coulee City and Electric City. The highway connects to Steamboat Rock via a natural land bridge.

Steamboat Rock is far enough from side walls of Grand Coulee that it can trick the mind into perceiving it as an uplift rising out of Banks Lake reservoir rather than as a remnant island of the surrounding Waterville Plateau. It is generally flat on top, except for a 100 foot-deep cleft that cuts across its width near its southern end. Geologists think the deep groove may have been initiated by a stream that pre-dated the glacial floodwaters. Thus, if the scene were not head-spinning enough, here you have a nested doll of geology: a canyon hanging in the sky on a peninsula within a 1,000 foot deep coulee.

In the midst of this grandeur Northrup Canyon can be overlooked, in large part because it’s not visible from the highway. Although there’s a Northrup Canyon sign on state route 155 it is not a large one. On a late summer day a few years ago I barely caught a quick glimpse of it as I was whizzing toward Electric City at 60 miles an hour. I drove for a mile, admiring the gnarly granitic outcrops that had suddenly come into view, and then did something I usually don’t do. I turned around, to see what I would be missing if I hadn’t turned around.

What I found and then wandered into was surreal and blessedly serene. A gravel road winds up through a crease in the ramparts northeast of Steamboat Rock. What’s immediately strange—given that the standard issue bedrock of the scablands is dark basalt—is that granite is now everywhere. And not just a few light-colored stones.

Near the mouth of Northrup Canyon, for example, is what the rock climbers call “Gibralter Rock.” It is a massive granitic monolith, towering well over 100 feet above the round pen of the canyon’s equestrian area.

A quarter mile further up the road—pinched between a granite ridge and the soaring basalt escarpment that frames the southern rim—is the canyon’s trailhead. By then a visitor will have noticed something unusual for this part of the Columbia Basin. Trees. Within view are hundreds of mature pines and a large grove of aspen and red-twig dogwood watered by Northrup Creek. The pines offer winter roosts for eagles and the riparian habitat along the creek supports a number of other avian species that attract birdwatchers year round.

What I found and then wandered into was surreal and blessedly serene.

The further you hike to the east, the wider the canyon becomes. It eventually branches with one broad arm headed off to the northeast, and the other to the southeast. The “Y” shape of the canyon enhances the dramatic relief Bretz wrote about nearly a century ago because there are soaring cliffs on three sides.

I’ll defer to the camera to better convey the surreal flood features of Northrup Canyon. But, to my eyes, the interplay between the granitic rock and the basalt is mesmerizing. To the north beyond Gibralter Rock, for example, there is not only a high, toothy rimrock of basalt, but parapets of granite. The granite is the true bedrock of the area and part of the same granitic pluton that anchors Grand Coulee Dam to the north.

The basalt came millions of years later and covered the granite. Then—in much more recent time—came the pulses of glacial floodwaters, which arrived with such violence as to strip away much of the weaker basalt cover, re-exposing the granite. One weird result is a low ridge of exposed granite in the middle of the lower canyon, with towering walls of basalt on either side. Here, on the north side of the granite ridge, Northrup Creek has naturally carved a gutter-like groove in the granite not far from where you can actually see, up close, the contact between basalt and granite.

The main trail into the canyon goes approximately three miles to Northrup Lake, a classic plunge pool surrounded by rimrock. It’s an especially popular trek in the fall, when the lake is surrounded by brilliantly colored foliage and the summer heat has passed. On the way out (and back) you’ll pass by the old Northrup homestead which is about where the trail turns northward and ascends into loose stands of pines and granite outcroppings.

From the trailhead near the canyon you can also find what is literally “the old wagon trail” that ascends the grade up to the top of the southern rimrock. But this trail is off-limits from mid-November to mid-March to protect roosting eagles.

The main trail can be very icy (from trampled and re-frozen snow) in the winter. Rattlesnakes are an issue in the summer, and I would recommend flashlights in spring and fall, just in case you linger longer than you may expect, and find yourselves hiking back in the fading light.

Next: The Bretz Hills

•The Teardrop Hills

A poem of geography, and the signature of a catastrophe

If it had been a game of cards, and not merely science, J Harlen Bretz had gathered a straight flush. Nearly a century ago, after two summers in the field, he was ready to lay out his provocative case that a great ice age flood had rampaged across eastern and central Washington.

Some pieces of his argument were so compelling they scarcely needed help from the other pieces.

There were, for example, large calves of rock that just happened to show up, unannounced and unexplained, in places far from their mother outcroppings.

Bretz had not been the first geologist to notice them. But part of what set him apart was the intensity of his curiosity. He was determined to find an explanation. He referred to the wayward rocks as “erratic bowlders.”

Erratics, by definition, are large rocks transported long distances by ice. What caught Bretz’s attention, as early as 1914, were the dozens of granitic and metamorphic “bowlders” found resting atop basalt bedrock as far south as the Columbia River gorge and as far away as the Willamette Valley. That was strange. Ice was the only plausible means of transport, but dozens of large erratics—many the size of refrigerators or larger appliances—were dropped far beyond the furthest, documented advance of the Cordilleran glaciers.

Finally, in 1923, Bretz played his hand. Consistent with his other field evidence, he proposed that the scabland erratics southwest of Spokane had been ensconced in glacial ice that had shattered and become flotsam in an enormous ice age flood. Although hang-gliding and zooming around on a jet ski are palpably exciting, it can also be fun to just close your eyes and imagine icebergs on the crests of towering waves that overwhelm Spokane and spill out into the Columbia Basin at highway speeds. And then, as the water recedes, the icebergs ground themselves on hillsides, melting and releasing their cargos of rocks and at least one large meteorite (the Willamette Meteorite, discovered in 1902) to boot.

Bretz’s explanation of the ice-rafted erratics was easily the most vivid among his quiver of arguments for the great flood. The others were more technical—i.e. the “braided” nature of scabland channels, the absence of glacial till, and the power of the floods to quickly remove astounding volumes of soil and underlying basalt. But one feature, in particular, was both poetic in the way Bretz described it and hauntingly graceful in the way it actually appears on the landscape.

I think of them as the Bretz hills.

As a rule, all Bretz hills were once Palouse hills. Palouse hills are known and rhapsodized for their mesmerizing, dune-like crests that are the signature landform of Whitman County, for decades the nation’s leading county in wheat production. The hills consist primarily of windblown loess—silt created by ice age glaciers grinding across the landscape, seasoned with volcanic ash. Loess is incredibly efficient at holding soil moisture, which helps explain the prolific crop yields in the Palouse.

Whitman County doesn’t have a monopoly on Palouse hills. Rolling hills of fine-grained loessial and volcanic soils extend into northern Idaho but also to the north, west, and south, including parts of Spokane, Lincoln, Adams, Franklin, Walla Walla, Grant and Douglas counties.

What makes a Bretz hill different from an ordinarily beautiful Palouse hill is that a Bretz hill is a survivor. It has withstood the onslaught of ice age floodwaters and been distinctively re-shaped. There are several places where you can see what happened, but my favorite is state route 23 between the towns of Sprague and St. John.

Generally speaking, the “prows” of Bretz Hills point toward Spokane—the direction from which the water came—and the tails toward Pasco, which is where the water would eventually pool before heading out toward the Pacific Ocean via Wallula Gap and the Columbia gorge.

Starting at Sprague and heading east, what you see is classic scabland—the surface scrubbed to the bedrock, with just enough grass growing among the sagebrush to feed grazing livestock. Basalt buttes are in all directions, and so are a remarkable number of lakes and wetlands. It is cowboy movie scenery.

After seven miles, the landscape changes. On your right is the Whitman County town of Lamont. If you were to take the turn-off toward Lamont what you would see on your right would be the gnarly scabland terrain you’ve just traversed.

On your left, however, would be bucolic Palouse. But if you look closely at the boundary hills—those bordering the scabland to the west—they are not classic Palouse hills. Because they’ve been overwhelmed by torrents of glacial floodwater, their shapes have been changed. Their slopes are steeper and they are stretched in length so that they look, from above, like elongated tear drops.

Of course, Bretz was offering the photographs of the flood-altered hills as evidence, not as art. After all, he clearly knew he was launching himself into a process that would involve years of arguments. It would take decades to win the arguments. But that wasn’t his fault. He was right to begin with.

This is a good place to hand the writing over to Bretz, from his 1923 paper:

“Literally hundreds of isolated groups of maturely eroded hills of loess stand in the scablands. Their gentle interior slopes are identical with those far from the scabland tracts. But their marginal slopes, descending to the scablands, commonly are very steep…” “A very striking and significant feature of the steepened slopes is their convergence at the northern ends of the groups to form great prows pointing up the scablands’ gradient…It is impossible to study these prow-pointed loessial hills, surrounded by the scarred and channeled basalt, without seeing in them the result of a powerful eroding agent which attacked them about their bases…”

Generally speaking, the “prows” point toward Spokane—the direction from which the water came—and the tails toward Pasco, which is where the water would eventually pool before heading out toward the Pacific Ocean via Wallula Gap and the Columbia gorge.

If you were to go even further south, through Lamont, you would soon lose the pavement and pass on to a gravel road that continues to follow the edge of the scablands. What you would eventually see on the distant horizon are a fleet of Bretz Hills, their prows aligned parallel to one other, as if sailing toward Spokane. They are but one example of the “isolated groups” of loessial hills that Bretz described—Palouse hills that somehow survived the great floods.

If you’d stayed on Highway 23—instead of turning off to Lamont—you would likely sense that you’d entered the heart of the Palouse. The highway quickly becomes a twisting ribbon through grain covered hills, their slopes sprawling in all directions. But seven miles later, the scene repeats itself as the hills abruptly end as you near Rock Creek and enter the eastern-most braid of the scablands—this one a bit more than four miles wide. If you were to look south, you would see Bretz hills in the distance, with their ghostly prows pointed north. Then the highway really does enter the heart of the Palouse and makes its way toward the Whitman County seat at Colfax.

There is an aesthetic quality to the scablands’ tear drop hills. Yet the story behind their survival and re-shaping creates a parable and quiet instruction on how to photograph them, or at least how to try.

As Bretz noted, the tear drop hills exist throughout the scablands, though they are more common in the easternmost tracts. The landscape along the lower Palouse River as it approaches Palouse Falls is another area where the tear drop hills are hard to miss.

In his 1923 paper, Bretz offered photographs of two isolated examples—one near Rock Lake and the other near Palouse Falls, south of Hooper. They’re small black & white photos that merely capture his point about the shape of the hills, both in slope and alignment. Of course, Bretz was offering the photographs as evidence, not as art. After all, he clearly knew he was launching himself into a process that would involve years of arguments. It would take decades to win the arguments. But that wasn’t his fault. He was right to begin with.

Whether it’s “The Sisters” at Wallula Gap, the massive cataract at Dry Falls, or the Stonehenge-like aura created by “The Feathers” at Frenchman Springs Coulee, there are several “oh my god” destinations in Bretzland that don’t need a story, let alone a caption.

In their graceful lines and isolation, the Bretz hills don’t need a story either. There is an aesthetic quality to the tear drop hills. Yet the story behind their survival and re-shaping creates a parable and quiet instruction on how to photograph them, or at least how to try. And, thanks to Bretz, I don’t feel as though I need to insert a compass for direction, or a pickup truck for scale. He’s done the hard work. I just need to get the camera to work.

–tjc

•Ground Zero at Green Monarch Ridge

At the climax of the Ice Age a massive glacier came face-to-face with the ancient basement rock of North America. Something had to give.

The nature of nature is that the new is generally trying to devour the old. In geology, the engine for this perpetual drama is largely hidden by seawater. In mid-ocean ridges volcanic forces push fresh terrain outward, creating huge plates of fresh rock that behave like slow-moving conveyer belts. When the plates inevitably collide, terrain buckles and melts under pressure, pushing up mountains and volcanoes, and lava.

A corollary to this overview are longstanding, stationary hot spots on the surface crust that convey blowtorch heat from the earth’s mantle. One such hot spot continues to create the Hawaiian islands. Another currently lies beneath the actively steaming caldera at Yellowstone National Park. On a map the Yellowstone hot spot appears to be moving eastward, but this is only because the North American plate is moving to the southwest.

Some 16 million years ago, the hot spot now beneath Yellowstone was situated about where corners of Idaho, Oregon and Nevada intersect today. Geologists think this is the reason more than 50,000 cubic miles of lava (basalt) spewed from hundreds of surface vents in western Idaho, northeast Oregon and southeast Washington. The peak of the vent eruptions was between 14 and 16 million years ago—with continuing smaller eruptions until about 5.5 million years ago.

The result is the black and brown bedrock that spans the lower Columbia basin and, in some places, is more than 10,000 feet thick. Basalt makes for beautiful palisades and dramatic rimrock cliffs and is otherwise ubiquitous in the lower Columbia Basin and through the Columbia River gorge. Witness, for example, the natural columns in road cuts around Spokane’s international airport. Yet, it would be a far less visible feature of the landscape were it not for Ice Age floods that violently stripped away the overlying topsoil.

On Green Monarch Ridge you can easily see and touch the ancient rock in outcroppings where the Purcell Trench ice lobe repeatedly rammed and sealed itself onto the mountainside, perhaps as recently as 14,000 years ago.

In geologic terms, it’s as though all of this just happened. If you condensed Earth history into a day, the basalt flows would have occurred in the last 5 seconds and the peak Ice Age floods in the last blink of an eye. But it’s eloquent, and perhaps fitting, that at least one character in the Bretzland story is over a billion years old and that you can still see it and touch it.

To do so, you’ll have to drive to Idaho and, lucky you, visit one of the Pacific Northwest’s most beautiful places, east of Sandpoint. Whether you get to Sandpoint via U.S. route 2, or U.S. 95, you’ll be headed toward a junction, north of town, where you’ll want to pick up Idaho state route 200. Route 200 follows the shoreline of Lake Pend Oreille which bends east and then southeastward toward the town of Clark Fork, where the Clark Fork River empties into Lake Pend Oreille.

Along the way, a good place to stop, enjoy the view, have a picnic and gather your bearings is the Trestle Creek beach and campground about ten miles out from Sandpoint.

At the shoreline, the view to the right (west) takes in the Selkirk Mountains and the slopes of the fabled Schweitzer Mountain ski resort. In the other direction, to your left, you can see the northernmost mountains of the Bitterroot Range, including Green Monarch Ridge with its western face plunging steeply into the lake. As unlikely as it may seem, this tranquil scene was ground zero for the epic floods that created Washington’s channeled scablands.

At a lakeside turnout a few more miles down the highway, just before the town of Hope, there is a roadside educational display. One of the large display panels tells the story of the Purcell Trench glacier arriving from the north—as tall as four Space Needles stacked atop one another—and pushing up against Green Monarch Ridge.

The massive glacier was unrelenting, but the Green Monarchs are built from some of the oldest and hardest rock in North America. These are layers of ancient sedimentary and metamorphic rock that accrued in what is known as the Belt Basin, essentially a vast inland sea that formed more than a billion years ago near the westernmost edge of what eventually became the North American craton. Belt Basin rocks are commonly referred to as the Belt Supergroup in the U.S. and the Purcell Supergroup in Canada.

Here’s a fun fact. When you’re done perusing the educational signs at the turnout near Hope, just turn around so that you’re looking across the highway. In the road cut beyond the westbound lane you’ll notice layers of exposed rock that are predominately the color of copper but with streaks of tan, white, gray and a dark chocolate shade of brown. It’s not just any rock. It’s an outcrop of the Prichard Formation which is the very basement of the Belt Basin, the oldest rock formation in western North America.

When the Purcell Trench ice sheet met the incredibly hard and old rocks at Green Monarch Ridge the collision created a seal—a natural ice dam 2,000 feet high, trapping the Clark Fork River in its valley. Consequently, a massive body of water, glacial Lake Missoula, built up behind the ice dam. Missoula, Montana, is nearly 200 miles southeast of the Clark Fork ice dam. There is clear evidence that the trapped floodwaters at Missoula were nearly 1,000 feet deep.

Under such accumulating pressure, the Clark Fork ice dam would periodically disintegrate (with a roar on par with a massive volcanic eruption or asteroid strike) sending an inland tsunami of ice-laden floodwaters racing toward Spokane at highway speeds. Based on the field evidence downstream, geologists think this happened not once, but at least dozens of times.

J Harlen Bretz put forth his theory of catastrophic flooding as the cause for the epic erosional features of Washington’s channeled scablands in 1923. He soon began referring to it as “the Spokane flood.” This is because it was obvious, at least to him, that the Spokane area had been a bottleneck through which most of the floodwaters had passed. According to Bretz’s biographer, John Soennichsen, the geologist was aware of ancient Lake Missoula by 1925. Yet he was reluctant, for several years, to connect the dots.

What what would eventually turn the tide was a finding that another northwest geologist, J.T. Pardee, first shared at a Seattle conference in 1940. There were giant ripple marks on Montana’s Camas Prairie northwest of Missoula. Pardee proposed that the fifty foot-high ripples were the result of sudden, massive draining of Lake Missoula—with the waters clearly heading westward, toward the Columbia Basin. Without explicitly saying so, Pardee was presenting the missing piece that clearly validated Bretz.

The scale of the story can be mind-boggling. It was a cataclysmic event that spanned time zones, a great wave of devastation the followed the curve of the planet from the alpine beauty of the northern Rockies to the bare hills and sage of the Pasco Basin, and the Columbia Gorge beyond.

Had Bretz’s great flood theory of the scablands been less controversial, Pardee’s finding (formalized in a 1942 paper) would have abruptly ended the debate. Yet—as Soennichsen recounts in his fine book Bretz’s Flood—the controversy dragged on for decades. It was a hollow debate which had far less to do with the geologic evidence than with the stature and hubris of the prominent geologists who’d dismissed Bretz’s theory from the start.

With science alone, it is difficult to capture the scale of the story, although I think you’d agree that the road turnout signs on Highway 200 near Hope do a pretty job, especially given the space limitations. The scale can be mind-boggling when one ties to comprehend a cataclysmic earth story that spans time zones, following the curve of the planet from the alpine beauty of the northern Rockies to the bare hills and sage of the Pasco Basin, and the Columbia Gorge beyond.

The timescale is also mind-bending. Bretz was nearly 100 years old when he passed and well into his late nineties when he was given his profession’s top award, finally recognizing his persistence and the quality of his work. It was a vindication that took far too long given the relative brevity of a human life.

On Green Monarch Ridge you can easily see and touch the ancient rock in outcroppings where the Purcell ice lobe rammed and sealed itself onto the mountainside, perhaps as recently as 14,000 years ago, maybe less.

Some of the intransigent rocks that greeted the ice front are 1.3 billion years old. Despite the current, human-induced warming trend, it’s likely there will be other Ice Ages, and more ice-damming collisions between the face of the Purcell Trench glacier and the Belt Basin rocks on Green Monarch Ridge. It’s the kind of long story that can repeat itself.

Time for lunch.

–tjc

Next Up: The Spokane Flood

•The Spokane Flood

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.

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.

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.

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.

Next Up: Frenchman Coulee

•Frenchman Coulee

How an obscure freeway exit can change your day, and perhaps your life.

Halfway between Spokane and Seattle, Interstate-90 dips to the southwest and descends from the open flatlands of Grant County toward the Columbia River. Although Frenchman Coulee is only a mile or so from the freeway it is unmarked and out of sight to motorists. This may explain why nearly everybody whizzes by one of the region’s premier natural landmarks at 70 miles an hour.

As a promoter of such wonders, a modest purpose of mine is to coax more visitors to places like Frenchman Coulee. I accept there is something liberating about the idea of leaving Spokane late in the morning, setting the cruise control, and arriving in Seattle in mid-afternoon. But my cordial argument is that it’s almost silly not to experience Frenchman Coulee (aka Frenchman Springs Coulee) at least once in your lives, and even better to experience it every once in a while.

With that gentle preface, here’s how to get there. Whether you’re headed west or east, the exit for the coulee is Silica Road at milepost 143. Silica Road loops through wetlands for a quarter mile before it intersects with Vantage Road. You’ll want to turn left here, onto Vantage Road. This can be confusing because—as some of you already know—Vantage is actually on the other side of the Columbia River. So, there is the paradox that Vantage Road will not take you to Vantage. Let’s overlook this, for now, and just make the left turn.

Vantage Road will take you downgrade and, within a minute, a breathtaking scene unfolds. As the pavement descends and bends south, the gaping, northern cataract of the coulee opens to a “V”-shaped chamber, with Vantage Road carved into the left arm of the “V.” The right arm of the “V” is the coulee’s magnificent west wall, complete with a thin white thread of a waterfall spilling from the sheer cliff to a moss-coated talus skirt far below.

My cordial argument is that it’s almost silly not to experience Frenchman Coulee at least once in your lives, and even better to experience it every once in a while.

It is startling how abruptly nature takes hold. The ocean of machine-groomed croplands that consume most of the modern Columbia Basin is suddenly out of sight. There are no trophy homes perched atop the rimrock. The cliff-lined river gorge is visible in the distance, and beyond the gorge the Cascade foothills rise west of the river, with the treeless shoulders of Whiskey Dick Mountain on the horizon.

The natural landmark within this natural landmark is called “The Feathers” and it will appear, on your left, a mile down Vantage Road. The Feathers are a curved formation of Roza basalt columns—very popular with the region’s rock climbers—that somehow survived the onslaught of Ice Age floodwaters that excavated the coulee. It is a freak of nature that The Feathers exist, as a defiant arc of pillars, some standing taller than forty feet.

The Feathers epitomize what amounts to a rather young (in geologic time) earth story that arrived in two dramatic chapters.

First, from roughly 15 million years ago, came a tide of lava. A portion of those molten outbursts—now catalogued as the Roza member of the Wanapum basalts—emerged from a vent system that extends from east-central Washington to the northeast tip of Oregon. Thus, if you passed through Ritzville earlier in the day, heading west, you can imagine what it must have looked like when a massive, orange and black sheet of molten rock rolled hundreds of square miles from what is now the Palouse all the way to the foothills of the Cascades.

Some basalt columns on the Columbia plateau are only as wide as your fist. But the Roza flow features some of the largest columns, and those that form The Feathers have the girth of railroad boxcars. No wonder people want to climb on them.

Of course, the second chapter in the Frenchman Coulee earth story has everything to do with the Ice Age floods during the late Pleistocene Epoch that ended just 11,700 years ago. As floodwaters rushed into the Columbia Basin from the north and east they filled and then overflowed a broad bowl (the Quincy Basin) between the Beezley Hills northwest of Ephrata and the Frenchman Hills northwest of Othello. The eastern exit for the basin’s floodwaters was through the Drumheller and Othello channels south of Moses Lake. Frenchman Coulee is the remnant of one of three places (Potholes and Crater coulees are the others) on the western margin of the Quincy Basin where floodwaters cascaded down a 600-700 foot slope to the Columbia River below—devouring and removing huge masses of soil and rock along the way.

There are several places in Frenchman Coulee where the broad views force a reckoning between the remnants of destruction and the grandeur of survival. The Feathers evoke comparison to Stonehenge. The coulee’s floor —with the tossed remains of smashed pillars plucked from the canyon walls—evokes a battlefield. It’s a lot to take in, even if you resist the urge to climb onto something, or stand too close to the edge of the basalt cliffs.

To these field notes there are footnotes:

•Silica Road takes its name from deep, ancient lake deposits of white diatomite that are visible on the coulee’s northwest rim, not far from the waterfall. Diatomite is mined for its silica content.

•Vantage Road was, at one time, the actual highway to Vantage (former U.S. highway 10), crossing the Columbia at a bridge that was dismantled once the I-90 bridge was completed a few miles downstream. The steel structure of the old bridge is now at another Bretzland landmark, helping to span the Snake River at Lyons Ferry State Park, below Palouse Falls.

•Whether you leave your car to hike, or climb, it’s a good idea to have a Washington State Discover Pass to hang from your rear view mirror. There are restrooms just down the road a ways from The Feathers.

Next: Palouse Falls