A Look Back at Ten Years of Geotripping: Vagabonding on Dangerous Ground, an Exploration of Cascadia

In 2015 I wrote a blog series about driving through the "Most Dangerous Plate Boundary" in the world, but it was actually about driving through a fossil subduction zone that is exposed in the Coast Ranges, Great Valley and Sierra Nevada of Central California. In the summer of 2015, Mrs. Geotripper and I took a long journey along the entire length of a real "dangerous plate boundary", the Cascadia subduction zone, that extends from Northern California to British Columbia. The trip coincided with a media explosion over the very real possibility of a magnitude 9 earthquake along the Pacific Northwest coastline. This resulted in another blog series, Vagabonding on Dangerous Ground. Here is a compilation of the journey...

This was posted on September 13, 2015...

I've finished a new blog series on our exploration of the Cascadia Subduction Zone, so I've compiled all the posts in chronological order so you can get the story the correct sequence. Thanks for all the nice comments, responses, and corrections! Click on the orange titles for the post.

On the Road in the Pacific Northwest: The introduction and overview of the new blog series.

Following the Cascadia Subduction Zone on Highway 101: This post provided the geological background for understanding the hazards of living in the lands influenced by the Cascadia Subduction Zone.

In This Land of the Sasquatch There are Ancient Giants: The first leg of our journey took us through the range of the California Redwoods and the land of black bears that look suspiciously like walking ape-people.

The End is Coming (of the Cascadia Subduction Zone): The end of Cascadia is a slow process, but the zone is disappearing slowly, being replaced by the San Andreas fault. It's also a look at one of the loneliest beaches in California.

A Geologist Walks Onto a Bar in Cascadia: Exploring the unique baymouth bars along the Humboldt county coast.

Northern California's Tsunami Central: Crescent City has a tragic history of tsunamis, especially the one in 1964 that took a dozen lives and destroyed the marina and downtown areas.

This "Dismal Forest Prison" and other problems exploring the Northwest: The Pacific Northwest was particularly difficult to explore and map, at least if you weren't part of the indigenous culture. Here are some accounts of the discovery of Humboldt Bay by land.

Into the Land of Sand, and Exploding Whales: Between Coos Bay and Florence, Oregon, is the longest stretch of sand beaches and dunes in the Pacific Northwest. Yeah, and the whale thing...

Into the Realm of the Devil (and Sea Lions): There are a lot of things named for the devil on the Oregon coast for some reason. And some incredible sea caves occupied by sea lions.

Putting on a Happy Face at Dismal Nitch and Cape Disappointment: We reach the mouth of the Columbia River, where Lewis and Clark reached their goal. It's undergone a great many changes over the years.

Into the Rainforest, Seeing Something Strange...Rain: We explore the Hoh Rainforest in Olympic National Park for the first time, and encounter something strange, at least this year: rain. There was also a fire burning in the rainforest. That's not normal.

The Diverse Landscapes of Olympic National Park: Olympic is one of the most diverse of our national parks, with alpine glaciers, rainforests, and coastlines. It's spectacular.

The Salish Sea and the Strait of Juan de Fuca: Glaciers and tectonics combined to form a seaway east of Vancouver Island and the Olympic Peninsula. It's a unique ecosystem quite distinct from the Pacific Ocean just a few miles away.

Stone Rings, Glaciers, and "Dinosaurs" on the Coast of the Salish Sea: Desecrated burial mounds, avian dinosaurs, and glacial landscapes. Victoria on Vancouver is both a beautiful city and a fascinating place to explore.

Exploring North America's Southernmost Fjord: We take the ferry to the mainland, making landfall inside of the southernmost glacial fjord in North America, Howe Sound in British Columbia (defined here as on the mainland, but connected to the ocean; opinions differ!).

Landing Place of the Thunderbird and the Grimy One, the Volcanoes of British Columbia: Black Tusk and Mt. Garibaldi two of the northernmost volcanoes in the Cascade Range. I missed them last year in the rain, but saw them this time.

Controversial Stone People, Fire and Ice, and an Olympic Legacy: We made it to Whistler and the home of the 2010 Winter Olympics. The stone people were controversial, but the scenery was not. It was spectacular.

Seeing Volcanoes from the Inside Out at Siám' Smánit (Stawamus Chief): Glaciers and granite! Stawamus Chief is a dramatic granitic dome rising high above the end of Howe Sound. It was once the magma chamber of a volcano.

Our Tour of the Greatest National Park I Never Once Set Foot In: North Cascades National Park is a true primeval wilderness. No roads penetrate the park boundaries. But what incredible scenery!

The Geology that Explains Why North Cascades is a Park Divided: The Skagit River may be the most altered water course in the Pacific Northwest, but it provides 20% of Seattle's electricity. It splits a national park in two.

What's East of North (Cascades), A Brief Explore: North Cascades doesn't have all the scenery; the lands to the east are rather spectacular too, and offer some great geology.

Playing Hide and Seek with a Sleeping Monster: Mt. Baker is not the most active volcano in the Cascade Range, but it is capable of great mayhem. It even looked for awhile like it might blow back in 1975.


Danger Follows Us Home (As it does all of us): A Mt. Shasta drive-by (photo) shooting, and a wrap-up of the series. Danger is always with us no matter where we are. It's not to be feared, but respected and prepared for.

Vagabonding on Dangerous Ground: A Compendium of Posts

I've finished a new blog series on our exploration of the Cascadia Subduction Zone, so I've compiled all the posts in chronological order so you can get the story the correct sequence. Thanks for all the nice comments, responses, and corrections! Click on the gray titles for the post.

On the Road in the Pacific Northwest: The introduction and overview of the new blog series.

Following the Cascadia Subduction Zone on Highway 101: This post provided the geological background for understanding the hazards of living in the lands influenced by the Cascadia Subduction Zone.

In This Land of the Sasquatch There are Ancient Giants: The first leg of our journey took us through the range of the California Redwoods and the land of black bears that look suspiciously like walking ape-people.

The End is Coming (of the Cascadia Subduction Zone): The end of Cascadia is a slow process, but the zone is disappearing slowly, being replaced by the San Andreas fault. It's also a look at one of the loneliest beaches in California.

A Geologist Walks Onto a Bar in Cascadia: Exploring the unique baymouth bars along the Humboldt county coast.

Northern California's Tsunami Central: Crescent City has a tragic history of tsunamis, especially the one in 1964 that took a dozen lives and destroyed the marina and downtown areas.

This "Dismal Forest Prison" and other problems exploring the Northwest: The Pacific Northwest was particularly difficult to explore and map, at least if you weren't part of the indigenous culture. Here are some accounts of the discovery of Humboldt Bay by land.

Into the Land of Sand, and Exploding Whales: Between Coos Bay and Florence, Oregon, is the longest stretch of sand beaches and dunes in the Pacific Northwest. Yeah, and the whale thing...

Into the Realm of the Devil (and Sea Lions): There are a lot of things named for the devil on the Oregon coast for some reason. And some incredible sea caves occupied by sea lions.

Putting on a Happy Face at Dismal Nitch and Cape Disappointment: We reach the mouth of the Columbia River, where Lewis and Clark reached their goal. It's undergone a great many changes over the years.

Into the Rainforest, Seeing Something Strange...Rain: We explore the Hoh Rainforest in Olympic National Park for the first time, and encounter something strange, at least this year: rain. There was also a fire burning in the rainforest. That's not normal.

The Diverse Landscapes of Olympic National Park: Olympic is one of the most diverse of our national parks, with alpine glaciers, rainforests, and coastlines. It's spectacular.

The Salish Sea and the Strait of Juan de Fuca: Glaciers and tectonics combined to form a seaway east of Vancouver Island and the Olympic Peninsula. It's a unique ecosystem quite distinct from the Pacific Ocean just a few miles away.

Stone Rings, Glaciers, and "Dinosaurs" on the Coast of the Salish Sea: Desecrated burial mounds, avian dinosaurs, and glacial landscapes. Victoria on Vancouver is both a beautiful city and a fascinating place to explore.

Exploring North America's Southernmost Fjord: We take the ferry to the mainland, making landfall inside of the southernmost glacial fjord in North America, Howe Sound in British Columbia (defined here as on the mainland, but connected to the ocean; opinions differ!).

Landing Place of the Thunderbird and the Grimy One, the Volcanoes of British Columbia: Black Tusk and Mt. Garibaldi two of the northernmost volcanoes in the Cascade Range. I missed them last year in the rain, but saw them this time.

Controversial Stone People, Fire and Ice, and an Olympic Legacy: We made it to Whistler and the home of the 2010 Winter Olympics. The stone people were controversial, but the scenery was not. It was spectacular.

Seeing Volcanoes from the Inside Out at Siám' Smánit (Stawamus Chief): Glaciers and granite! Stawamus Chief is a dramatic granitic dome rising high above the end of Howe Sound. It was once the magma chamber of a volcano.

Our Tour of the Greatest National Park I Never Once Set Foot In: North Cascades National Park is a true primeval wilderness. No roads penetrate the park boundaries. But what incredible scenery!

The Geology that Explains Why North Cascades is a Park Divided: The Skagit River may be the most altered water course in the Pacific Northwest, but it provides 20% of Seattle's electricity. It splits a national park in two.

What's East of North (Cascades), A Brief Explore: North Cascades doesn't have all the scenery; the lands to the east are rather spectacular too, and offer some great geology.

Playing Hide and Seek with a Sleeping Monster: Mt. Baker is not the most active volcano in the Cascade Range, but it is capable of great mayhem. It even looked for awhile like it might blow back in 1975.


Danger Follows Us Home (As it does all of us): A Mt. Shasta drive-by (photo) shooting, and a wrap-up of the series. Danger is always with us no matter where we are. It's not to be feared, but respected and prepared for.

Vagabonding on Dangerous Ground: Danger Follows Us Home (As it does all of us)

Mt. St. Helens from Silver Lake

We have finally reached the last few days of our meandering journey through the lands influenced by the Cascadia Subduction Zone. We spent several weeks out there, checking out the landscapes threatened by a possible magnitude nine earthquake. Although the hazard has been recognized for quite a few years, there was a media storm over the summer that brought the dangers into focus for the people living in the coastal zones of the Pacific Northwest. We were on our vacation anyway, traveling up the coast, but our search for beautiful scenery became an exploration of geological landscapes threatened by earthquakes, landslides, tsunamis and floods.

After many days in Oregon, Washington and British Columbia, we were on the homeward road, traveling hundreds of miles a day, knowing that issues at home needed attention. It didn't leave much time to investigate the other danger facing those in the northwest: volcanic activity. We got to see Mt. Baker for the first time, and Mt. Garibaldi, but Mt. Rainier and Mt. St. Helens were hidden in the clouds (we had a brief view of St. Helens from Silver Lake; see the first picture). Mt. Hood, the Three Sisters, Crater Lake, and all the other Cascade volcanoes were hidden behind the forested ridges. We couldn't see them from the freeway, and we had no time for detours.

But then we crossed back into California, forded the Klamath River, and surmounted a ridge where a gigantic mountain came into view. It was Mt. Shasta (14,179 feet / 4,322 meters), one of the southernmost volcanoes in the Cascade Range (Lassen Peak is down that way too). Although it is a few hundred feet shorter than Mt. Rainier, it has much more volume. Not only is it the largest volcano in the Cascades, it is the second most active, exceeded in that department only by Mt. St. Helens. Eruptive activity occurs every 600 years or so. The last eruption was an ash explosion 200-300 years ago, possibly witnessed in 1786 (this is disputed; wildfires can look much like volcanic eruptions).

Like any active volcano, Shasta is dangerous. It's not just lava flows (that Hollywood staple), but potential ash flows, and volcanic mudflows (lahars), made all the more likely by the presence of California's largest glaciers around the summit. Many times the lahars occur without eruptive activity (at least 70 times in the last 1,000 years) as glaciers melt in the warmer seasons. Most of the towns near Shasta are built atop lahar deposits (around 10,000 people live in the immediate vicinity of the volcano). 

The pictures in this post are unique in one sense; they were mostly taken from a moving vehicle (by Mrs. Geotripper; I was trying to concentrate on driving). We had come 250 miles already, and had another 250 before we would get home, so we just didn't have time to linger. Driving does give one time to think, though, and I was thinking about the nature of geologic hazards.

We had just spent weeks traveling through a region that could potentially be devastated by an entire buffet of disasters. And yet millions of people live there, either unaware or willing to take the chance in order to enjoy the amenities of living in a coastal paradise, or someplace incredibly green and scenic. I felt no sense of relief from getting out of that danger zone because I understood that any one of those disasters had a very small chance of taking place while I was there. Even if something had happened, we were stocked up and prepared to be on our own for upwards of a week or more. But the clock was ticking, and the longer one stays, the greater likelihood that something bad will happen.

But a geologist's perspective provides little comfort. Going home to familiar ground was no protection from geologic disaster, whether sudden or over decades. I live in a flat and (dare I say it?) boring place, and yet I face geologic disasters every day. I live only about fifty miles from the San Andreas fault, and just twenty or thirty miles from lesser-known but active faults. I live next to a major river that is prone to flooding every few years. My town is just eighty miles or so from a rhyolite caldera that is more active than the "supervolcanoes" of Yellowstone National Park. And for the last four years we have been suffering through an unprecedented drought unlike any ever faced by modern-day California (although precedents exist in the recent geologic past). There's no escaping the Earth, and no one is immune from disaster.

Sutter Buttes from the Sacramento National Wildlife Refuge, the remnants of a Cascades-style volcano in the Great Valley of California. Wait, what? A volcano in the Great Valley???

As we drove through Sacramento in the late afternoon, we could see the very strange skies produced by an out-of-control wildfire in the Coast Ranges. It was too close for comfort, and even as I write this fires are burning very close to the homes of friends in the Mother Lode (100 square miles and only 10% contained), and one of my most precious of landscapes, Kings Canyon in the Sierra Nevada, has gone up in flames (200 square miles already incinerated). In my life, these places will be forever changed, and for the lives of those in the path, their lives will be forever changed.

If geology and earth science teaches us anything, it is that we can't avoid disaster no matter where we go. You don't like earthquakes and volcanoes? Fine. Move to Kansas and enjoy the tornadoes, heatwaves and droughts (I used to say Oklahoma, but they have more earthquakes now than California). Move to Florida and enjoy the hurricanes and the unstoppable rise of coastal flooding. Every place on Earth that I know of faces some kind of event that is incompatible with human existence. And in a strange way, that's what makes us human: we evolved in a dangerous world, and occasionally we are reminded of this in tragic ways.

So how do we respond? Being the teacher that I am, I say the first priority is to educate yourself. Learn what geologic forces influence the place where you live. Learn what the real chances are of such events (don't depend on sensationalist sources in the media or the internet; they want viewership, and aren't really interested in actually educating anyone). Use the resources of the U.S. Geological Survey, or your state geologic surveys (except Oklahoma; for a long time the government there didn't allow the geologists to say that the earthquakes were man-made). Once you know what the threats are in your area, ask yourself what you would do to protect yourself if they were to happen today. Are you prepared? Can you make it through several days or a week or more without water, power, communications? Or the internet? What have you done to be ready? Or, will you be one of the many who will have to wait for the arrival of government assistance?

Am I trying to make you paranoid? Not at all. Paranoia comes from ignorance. If you know what could happen, and you have a plan, you've got the best possible chance to be okay. I can only relate the story of the time I came closest to death. It was two years ago on the Colorado River in the Grand Canyon. Because the river emerges from the deepest parts of Lake Powell, the river is at a constant 47 degrees or so, even when the ambient temperatures in the desert environment exceed 110 degrees. Hypothermia is one of the greatest dangers facing any river rafter. I was anxious about the possibility of a raft flipping in one of the rapids, because more than a few people have died in such circumstances. I worried, but I also practiced in my head, over and over, what I would do if it happened. And I never went into the river without a life preserver.

And of course it happened. We had come through dozens of huge rapids, and one could say that I was almost complacent as we approached Crystal Rapid, one of the two most violent rapids on the river. But the boat flipped in a heartbeat and I was in the river (see the whole story here). Knowing myself, I would have expected to panic, but the mental training took over instead. Although I was in the middle of watery chaos, I was able to get to the overturned raft, which made me easier to find, and I was positioned correctly when I started bouncing off boulders in the river. I was okay in the end, though very shaken. And it was because of the preparation and training provided me by my fellow travelers on the river.

And that's the message I leave with you at the end of this latest blog series. We all live on "dangerous ground". There is no place where we can escape the normal processes of the Earth. But we can choose where to live and what dangers to face, and prepare accordingly. And we can take care of each other when the disasters come.

I hope you've enjoyed the journey! I'll be compiling all the posts in one place soon.

Vagabonding on Dangerous Ground: Playing Hide and Seek with a Sleeping Monster

Mt. Baker and Boulder Creek upstream of Baker Lake Reservoir

There's something about traveling through the Pacific Northwest that I may never become accustomed too: the deep, deep forests. As a child in the scouts, living in arid Southern California, I was pretty good at orienteering with a compass and map, but that was predicated on the fact that I could see the mountains around me. That would have been tougher if I had grown up in a rainforest. Every view is of a tree!

And so the struggle to actually see Mt. Baker in the Cascade Range. We had actually traveled around three sides of the mountain in the last two days, but I never got much of a glimpse, either because of the deep forest, or, you know, having to pilot the car without plowing into a tree or a deer. We finally got serious about the effort by detouring onto Baker River Road as we left North Cascades National Park. The road would take us within six miles of the summit as the crow flies. If we couldn't see it from there, we didn't deserve to see it.

This web series was entitled Vagabonding on Dangerous Ground primarily because we happened to be following the coastal parts of the Cascadia Subduction Zone which had become newsworthy over the summer because of a New Yorker article detailing the probable damage from an expect magnitude 9 earthquake offshore. Shaking, tsunamis, landslides, power disruptions and many other frightening events were part of the article. Kind of lost in the whole media affair were the sleeping giants that have always been a visceral threat to those who live in the region: the volcanoes.

In Cascadia the subducting slab of cold oceanic crust and underlying solid mantle material (the lithosphere) are driven into the much hotter asthenosphere, a "mushy" layer in the mantle that is partly molten. The interaction of the slab, water from the oceans, and the hot mantle rocks causes melting of some of the continental crust, forming magma that rises through the crust as a series of plutons. When they cool before reaching the surface, they will form visibly crystalline rocks like granite or diorite. When they reach the surface in a molten state, magma mayhem ensues.

The molten flows of lava that Hollywood seems to love the best are often the least serious problem during an eruption of a Cascade volcano, if they occur at all. More often any lava flows will melt prodigious amounts of snow and ice, producing volcanic mudflows (lahars) that can flow for tens of miles, causing damage at great distances from cone. In ancient times lahars could strike without warning from an eruption that couldn't be seen from within distant downstream canyons.

Some lahars aren't even associated with volcanic eruptions. They can be triggered by landslides on the upper reaches of the steep cones, or by unusually high amounts of glacial melting (water trapped under the glacier may burst out all at once). Mt. Baker has the most snow and ice of any Cascades volcano except Mt. Rainier (and that's a big except, as Rainier has about 50% of all the ice in the lower 48 states). So lahars are the big danger from Mt. Baker.

The other dangers result from explosive eruptions that pulverize the magma and other rocks around the summit of the volcano. The fine dust that results is called volcanic ash. The ash can be so hot close to the volcano that it can be incandescent. Anyone or anything caught in the fast moving ash flows is doomed, plain and simple. An ash eruption hit the Martinique town of St. Pierre in 1902 and killed all but two of the town's 30,000 inhabitants. These hot ash flows are called pyroclastic flows, or nuée ardente, French for "fiery cloud". The good news in the case of Mt. Baker is that relatively few developments are close enough to the peak to be threatened. But there are some.

Hazard areas in and around Mt. Baker in northern Washington

We found great views of the volcano from the dam at Baker Lake, and from Boulder Creek. Boulder Creek also provided a nice view of some lahar deposits as well, possibly from events in 1843 or 1891.

Mt. Baker is one of the youngest of the Cascade volcanoes, having formed mostly in just the last 30,000 years. The last major eruptions took place around 6,600 years ago when large lahars swept down creek valley accompanied soon after by ash eruptions. The 1843 eruption was caused by a hydrovolcanic explosion (groundwater flashing to steam). That event left behind Sherman Crater. In 1975, there was a vast increase in the amount of thermal energy around the summit of the mountain, raising fears of an eruption. The heat subsided somewhat, and everyone forgot about Mt. Baker when Mt. St. Helens exploded just five years later.

Lahar deposits at Boulder Creek near Mt. Baker

We were seriously on the homeward path now. No meandering highways along beautiful coastlines for us anymore. Interstate 5 was going to be our pathway now as we pushed south. But the Cascadia Subduction Zone had one more beautiful surprise for us. We'll wrap up our journey in the final post soon!

Vagabonding on Dangerous Ground: What's East of North (Cascades), A Brief Explore

Our vagabonding trip through the geologically hazardous territories influenced by the Cascadia Subduction Zone was mostly an unrushed affair as we meandered up the Pacific Coast through Northern California, Oregon, Washington and British Columbia. Towards the end, though, were realized we had spent most of our summer on the road and certain duties needed attention before the start of the school year (you know, that whole "writing syllabi, ordering textbooks, and cleaning the lab" kind of thing). So our last few days were very short explorations of some very beautiful places that I must return to as soon as possible. One of those places was the North Cascades National Park Complex (the park itself and two adjacent National Recreation Areas).

Our brief drive included a look at the "gorgeous" Skagit River Gorge and the large hydroelectric dams that utilize the high gradient river to produce a fifth of Seattle's electricity. We took advantage of the extended late-afternoon light to explore a little farther up Highway 20, which took us east of the national park. We had trouble telling the difference...it was just spectacular. We drove to the first summit at Rainy Pass, and saw there was another pass just a few miles way, so we went there too. 

Washington Pass (elevation 5477 ft./1669 m) was truly stunning, especially for a person like me. I've traveled a lot, but often visit the same places over and over, with students along. I enjoy the looks on their faces when they see something they've never seen before, but I don't get that thrill of "the first time" all that often. I got it here!

A short trail led to an overlook of the Liberty Bell and Early Winter Spires, a group of highly jointed granitic towers. There are popular climbing routes among the cliffs. The rocks are part of the Golden Horn batholith, an intrusion of granite dating to 48 million years ago.

Looking south we could see Kangaroo Pass. The rocks on the right side of the pass are part of another intrusion, the much older Black Peak tonalite. It dates to around 90 million years ago. The bowl at the head of the valley is an example of a cirque, the origin point for the glacier that flowed down Early Winter Creek during the ice ages.

The prominent peak in the center of picture above is Silver Star Mountain, with Vasiliki Ridge to the left, and Kangaroo Ridge to the right. The entire ridge is composed of the Golden Horn granite. One might wonder why this glacial valley of granite doesn't display domes like those of Yosemite. It's the joints. They are too closely spaced for exfoliation and dome formation to take place. It gives the entire region a sense of extreme ruggedness, and indeed the highway itself was not completed until 1972, after decades of seeking workable routes over the North Cascades.

The road descends north through the glacial U-shaped valley of Early Winter Creek.  We didn't have time. We turned back and headed down to camp in the Skagit Gorge in the setting sun.

There was one more "never-before-seen-by-me" mountain in the area. We'd be looking for it the following morning.

Vagabonding on Dangerous Ground: The Geology That Explains Why North Cascades is a Park Divided

Diablo Reservoir below the peaks of North Cascades National Park. The Turquoise color results from fine silt and clay derived from glaciers.

As I described in my last post on vagabonding, North Cascades National Park is the most strikingly beautiful national park I visited but never set foot in. The reasons become immediately clear with a look at the map of the park. There are two roadless sections, the North Unit and South Unit, and they are separated by the Ross Lake National Recreation Area along the Skagit River. And we unfortunately didn't have enough time for extensive hiking.

The human reason for the separation of the two park units is explained readily enough. Most national parks are established for their wilderness, geological, biological or historical values. They are not generally established to praise the engineering works of humankind. There are a series of dams and hydroelectric generating facilities in the Skagit River Gorge, and as such, they are administered as a series of national recreation areas. All of the parks and recreation areas were established at the same time, and are jointly administered by one bureaucracy. Because of the easier access (i.e. actual paved roads), the recreation area receives 750,000 visitors each year. The national park is visited by around 20,000 people a year. It would be fair to say that most of the visitors to the Ross Lake unit are there to appreciate the beauty of North Cascades. From a distance...

It turns out that geology had a lot to do with the circumstances leading to a separation of the two park units. We put dams where they will store as much water as possible, and that usually requires the presence of large rivers and drainage basins. Were it not for a geological event a few hundred thousand years ago, the Skagit River would have not been an appropriate place for a series of huge reservoirs (Ross Lake, for instance, has a capacity of 1,435,000 acre-feet of water. The lake is 22 miles long and extends into Canada). Prior to the ice ages, the Skagit River was a relatively small river, and the drainage did not cross the divide between the two park units as it does today. Instead, the ancient headwaters of the Skagit flowed northward into Canada, becoming part of the Fraser River drainage.

The ice ages put an end to that. A huge lobe of ice flowed south out of Canada, blocking the flow of the upper Skagit. The river backed up into a large lake, and eventually the lake breached the rim at a different location and started flowing west. The meltwater from the glaciers added to the ability of the river to carve downward, and the Skagit River Gorge was quickly cut (at least in geological terms). The river that flowed west was now many times larger, and the Skagit Gorge was too much of a temptation for any dam engineer to resist. Three reservoirs were built, Gorge, Diablo and Ross, and today they provide around 20% of the electricity used in Seattle.

So, today we have one of the most beautiful alpine regions in the Pacific Northwest, and a once small river made far larger by a quirk of geological history. It was a marvelous sight, but there was more. We drove beyond Ross Lake and headed for the high passes beyond. More next time...

Vagabonding on Dangerous Ground: Our Tour of the Greatest National Park I Never Once Set Foot In

Photo by Mrs. Geotripper

The western slope of the Cascades Range is green. Very green. There are trees, shrubs, mosses, grasses, just about every kind photosynthesizing plant there is. This is due of course to the mountains themselves. They provide a barrier to incoming Pacific storms, causing the moist masses of air to rise and condense, with copious amounts of rain and snow falling to the ground. We were still in the realm of the rainforest.

Photo by Mrs. Geotripper

We were on the southbound road towards home following our exploration of the coastal belt of the Cascadia Subduction Zone. We were on vacation, but we happened to be in the region when the New Yorker article about the coming magnitude 9 earthquake hit the stands. All of the sudden, it was the talk of the town (if you were in Seattle or Portland, anyway). So our trip became a blog exploration of the fascinating geology and natural history of the region.

Photo by Mrs. Geotripper

We had spent nearly a week exploring the coastal belt of British Columbia, but now we were back over the border into northern Washington. We were inland now, following the chain of volcanoes that result from the melting of the rocks above the sinking slab in the subduction zone. We had already seen the Black Tusk and Mt. Garibaldi in Canada, and were now looking for the northernmost volcanoes in Washington. They were hard to find in the thick forest!

Photo by Mrs. Geotripper

We headed up the Skagit River to pay a visit to what I believe is the only remaining national park in the western contiguous states that I hadn't been to yet: North Cascades National Park. We found a space in the park campground, and moved on to the visitor center nearby. We weren't seeing many Cascades mountains or volcanoes. We also had not yet, and would not ever set foot in the national park during our visit.

Photo by Mrs. Geotripper

The thing is, North Cascades is a wilderness park. No roads reach the interior of the park, and the only road that crosses the range doesn't pass through park lands. The Skagit River has been dammed for power generation, and the valley between the north and south units of North Cascades is administered as the Ross Lake National Recreation Area. Our campground and the visitor center are both on Ross Lake lands. I wasn't sure how much of the park we would be able to see during our short visit. We didn't have time for long hikes, and the main road between the two units was ensconced in a steep gorge.

We could see a few peaks above the river, but they weren't the glacial alpine peaks I was expecting to see. It was deep forest everywhere. Where were the rocks?

Photo by Mrs. Geotripper

From the visitor center, a short nature trail promised a view. We walked over to take a look, and mountains appeared out of the greenery!

Photo by Mrs. Geotripper

The visitor center was on a bluff above the Skagit River, and the viewpoint provided a vista up Goodell Creek towards the Southern Picket Range. The Pickets rise to 8,000 feet, and expose granitic and metamorphic rocks that have been scoured by glaciation. Glaciers still cling to the highest ridges.

One peak really stood out from the others. It's called Pinnacle Peak, or "The Chopping Block", and has an elevation of 6,805 feet (2,704 meters). The summit area preserves a bit of the relatively flat pre-glacial topography. The ice age glaciers chipped around the edges, but didn't remove it all.

Having found some rocks at last, we started looking at the maps to see if we could find more. I had no idea what was about to come next! More next time...