Travels in Cascadia: The Toughest Hike I'll Ever Do...Stawamus Chief in British Columbia

Note that I didn't say the toughest hike YOU will ever do. Every hiking experience is individual, and this one left me...breathless. Stawamus Chief is one of the most popular hikes in the Vancouver-Squamish region of British Columbia, and when we passed through the area last July, I knew I needed to give it a shot.

Stawamus Chief is a granite dome that rises more than 2,000 feet above the east end of Howe Sound, the southernmost fjord on the west coast of North America. The dome actually has three summits, the 1st, 2nd, and 3rd, and the trail climbs to the first summit in a little over a mile. That doesn't sound so bad, does it?

The beginning of the trail is pleasingly flat, rising gently through the Stawamus Chief Campground. The wide flat trail offered no clue about what would follow. I know it sounds dramatic, but from the moment one takes the first step upward as the trail starts the climb in earnest, the trail is relentless and steep.

Some of the steps are on wood stairwells, but the rest of them are large uneven stone blocks that I found challenging. And there are no breaks. Many trails are steep, but most all of them have short breaks were the trail is level for a few steps. Not this one. It never stops climbing.

I climbed higher and higher, and grew more exhausted with each step. The thought was slowly building in my head that I was no longer young, and that some trails were simply too tough for overweight 60-somethings. But then another thought immediately followed: this quite probably was the only chance I would ever have at making the summit. Who could know if I would ever be here again, and with time marching on, my ability to climb would no doubt degrade with age. It was probably the toughest hike I would ever do (in the future sense). I decided I had to do it, and kept going. And going.

Everyone's experience will differ, of course, and some younger and healthier people would not have that much of a problem on this trail. Part of my own worries weren't so much the climb, but the descent. All of those huge steps had to be repeated, but going down, and I worried about the impact on my knees and ankles. But I had already come so far.

Stawamus Chief is a granite dome, and the resemblance to Half Dome in Yosemite Valley is unmistakable. One of the things about Half Dome is that it was never covered with glacial ice. The dome took it's iconic shape from exfoliation of the outer slabs of granite. The corners and edges snapped off as the pressure of burial was released upon exposure to the surface. Glaciers at the base quarried away the fallen rocks.

Stawamus Chief was different: as I approached the summit, a most unusual rock emerged from the trees. It was a boulder perched on a granite platform. It was a classic example of a glacial erratic, a rock left behind as the glaciers that flowed over this surface melted away. Unlike Half Dome, the summit of the Chief had been covered by glacial ice. And not just a little...the ice here was over a mile thick!

In the end, I didn't make the true summit. The young men in our group reported that another twenty minutes and 200 feet of hard climbing remained ahead. I just wasn't up to it. But I did make it to the summit ridge, which provided a stunning view of the eastern end of Howe Sound. From this elevation, the glacial origin of the fjord was obvious. And I was happy to be where I was. Elated, even. And thrilled to be alive (literally!).

The knees and ankles took the expected pounding on the way down, but no lasting damage was done. I would live another day, and take on the next challenge. It could well have been the toughest hike that I would ever do (in the future sense; I've done some really tough hikes over the years), but the neat thing about life is that you never know what comes next. Maybe I won't do this trail again, but there are many other trails and challenges ahead. Again, that sounds dramatic, but finding one's limits is always an exercise in drama.

Bug Art at Beetle Rock

There is always something new to see when you are on the road. We were exploring the geology of Sequoia National Park for a field class this last weekend, and we saw many marvelous and beautiful things, but this was a new one for me.

We were at Beetle Rock, an exfoliation dome in the Giant Forest area of the park. The view was wonderful, but I noticed the oak trees at the edge of the clearing seemed "off". There was a mixture of green and brown in the foliage, and it wasn't fall colors. A closer look revealed feeding trails of some kind of insect, perhaps some sort of Leaf Miner (I would appreciate some help with identification, bug people!).

I don't know if this extensive pattern of feeding is detrimental to the health of the tree. There are a lot of changes happening in the Southern Sierra Nevada as a result of extended drought and climate change, and the number of dead conifer trees was truly depressing. I'm worried that something has also made the oaks susceptible to insect attack.

I've not noticed this sort of thing in the past, but then again, I've been known to not pay close attention to plants when there are rocks to look at. And the rock at Beetle Rock is pretty interesting. I just wasn't expecting actual beetles...

Ongoing Exfoliation Event at Twain Harte Lake in the Sierra Nevada

There is an ongoing geological drama going on the Sierra Nevada that may be unique (to the extent of my knowledge, which is admittedly limited in this area). Exfoliation, a process long recognized as the shaper of granitic domes and monoliths, is presently busting up the surface of a small dome at Twain Harte Lake a few miles east of the Mother Lode town of Sonora. The process has been captured on video, and is presently being monitored, due to the effects it is having on a reservoir abutment.

The event burst into the news in August when a possible dam failure warning was issued following a loud popping sound and the leakage of water from the edge of the reservoir. Once the site was investigated, a decision was reached to drain the lake until the full extent of the damage was clear. There have been at least three 'events', the last on August 3.

An employee of the lake association was very kind and allowed me to have a look at the dome and the new exfoliation shells. It was fascinating. The first thing to catch the eye was the lifeguard tower. It's tilted at an odd angle because the rock it is sitting on has been pushed upward into what is called an "A-tent" joint. My erudite and learned comment was "wow"!

Exfoliation is the breaking and fracturing of hard rocks like granite in slabs parallel to the surface of the rock. It removes corners and edges, resulting in the familiar domes found in regions like the Sierra Nevada where lots of granitic rock is exposed. It has traditionally been described as the result of 'unloading', whereby erosion strips off the overlying rock, releasing pressure and causing the rock to expand outwards, and fracturing in the process. There are some alternate explanations involving a certain amount of compression, which makes sense looking at the 'A tent' in the picture above.

There were freshly loosened slabs all over the surface of the rock, with lots of chipped edges. From the videos it is clear that the chips often snapped loose before the major slab event, like foreshocks to an earthquake (and given that earthquakes are also an example of stress release, the analogy is appropriate).

How incredible it must have been to see this happen!

The worry, of course, is the proximity of the exfoliation slabs to the abutment of the dam. A geological consulting firm is monitoring the activity, with stress meters set up in several places.

I admit I never gave it any thought, but it seems clear that the fractures are occurring in a swarm, as the stress regime changes with each break, placing new pressures in different sectors. Like a series of aftershocks following an earthquake, the rocks will continue to shatter for a period of time until a new stable regime or equilibrium is reached. I don't know any details of how or if this process has been witnessed in the past, so I couldn't even speculate on how long these rock 'pops' will continue. Maybe they are already done, but I wouldn't count on it.

The picture below shows a series of fresh parallel fractures running perpendicular to the edge of the dam.

We took a closer look at the dam abutment. So far the damage is limited to the top few feet of the south margin of the dam.

In the picture below we are looking down on the edge of the dam and on the left one can see the fresh exfoliation fracture. It leads into the dam abutment.

In this next picture, we are looking closer at the edge of the dam and can see a crack running through the concrete, going down about three feet or so. The dam is around 70 years old, and had been inspected only a few months prior with no signs of problems.

No one can say that the episode is over with, but it was fascinating to see. As I said before, I'm not aware of whether this process has been monitored in real time before, and I can't find any examples of exfoliation being captured in action on film or video, although it most assuredly is happening all the time somewhere in the world. If I hear of any developments, I will pass them on.

Picture by Mrs.Geotripper

I certainly hope the good people of Twain Harte get their lake back. It looked pretty sad without any water. It is a popular swimming and fishing hole.

If you haven't seen the video, there are some very good ones on the web, courtesy of Condor Earth Technologies (click here for the link) and Dotysan, who is a local resident. Check them out!

The Other California: Springtime along the Great Western Divide

Lupines along the Kaweah River gorge (Moro Rock and Alta Peak in the distance)

The Great Western Divide? Where's that?

My off and on blog series on the Other California is an exploration of the little-known places in my fair state with interesting, even fascinating geological features. Sequoia National Park might seem too familiar a place to be included as part of the "Other California", given that my own definition of the series is that it should include those places that don't normally show up on postcards, and Sequoia National Park certainly does.

So why include Sequoia? The primary reason is that it actually is less known than other parts of the Sierra Nevada. Ask folks where they go in the Sierra, and Yosemite Valley or Lake Tahoe are often the first places mentioned. And people often come to the park not so much for the geology, but for the biology, mainly to see the trees after which the park is named. But the park has a rich geological heritage as well.

Moro Rock from the Kaweah River gorge

The shape of the Sierra Nevada is often described as a tilted block of granitic rock and metamorphic rocks. That's true in the Sierra Nevada north of Sequoia. Driving to Yosemite National Park from the west involves a gradual climb up the western slope that continues to the Sierra Crest before dropping precipitously into the Owens Valley or Mono Lake on the east. Sequoia and the Southern Sierra Nevada is quite different. When one arrives from the west (which actually is the only way in which the park can be approached by roads), the road climbs steeply to a plateau, and the slope continues to a high crest. But not of the Sierra Nevada. It's an entirely separate mountain ridge called the Great Western Divide. The actual crest of the Sierra Nevada lies farther east, across the deep gorge of the Big Arroyo and the Kern River.

The Great Western Divide is a spectacular mountain range. It rises nearly to the height of the actual Sierra Crest, with several peaks exceeding 12,000 feet in elevation (A dozen or so peaks on the Sierra Crest reach 14,000 feet). Despite being far to the south, the peaks were high enough to be scoured by the glaciers of the Pleistocene Ice Ages.

A few weeks back we had the chance to pay an early springtime visit to Sequoia National Park. We came in from the west, up Highway 198 along the Kaweah River through the town of Three Rivers, and then up the Generals Highway to the Sequoia groves for which the park is justly famous. The road is notably curvy, and climbs through a rugged canyon choked with giant boulders that have tumbled from the cliffs above.

We soon passed one of those kitschy things that Civilian Conservation Corps workers in the 1930s seemed especially fond of constructing: a drive-through rock (to go along with "drive-through" trees). They enlarged the opening under the immense boulder, and put the road through it.

If one wonders why the road today circumvents the rock tunnel, one need only look at the underside of the boulder. People driving in scenic national parks are not known for paying close attention to their driving, and in a time of massive recreational vehicles, this kind of thing just doesn't cut it anymore.

A hat tip to the arrival of spring in the Sierra Nevada...the redbuds were in full bloom up the canyon, providing a splash of vivid color on the dark green slopes.

Although not as colorful as redbud, the ceanothus shrubs added a wonderful fragrance to the air. The bees and other pollinating insects were in heaven.

As we went further up the canyon, Moro Rock loomed ever higher above us. The granite rock of the dome expanded as the rock was exposed at the surface. The plutonic rock tended to fracture parallel to the surface, which had the effect of removing corners and edges from the rock outcrop, eventually leading to the formation of the dramatic dome. The process is called exfoliation. It would be so cool to climb the dome, but we knew that most of the park access roads would be closed because of the winter snowpack.

Except that they weren't. When we reached Giant Forest, there were a few snow patches here and there, but the snowpack is currently at half the normal level. All the roads were open, so we headed over to the Moro Rock trailhead. As dramatic as the dome is, trail access is easy because the CCC put in a stairwell to the summit. Easy that is, if you don't have problems climbing 300-400 steps. The views in the clear spring air were stunning.

Immediately across the Kaweah Gorge were the Castle Rocks (9,000+). The spires and towers of granitic rock exhibit the other result of rock expansion: jointing. When the fractures that result from pressure release are vertical, they allow water to get into the narrow spaces. If the water freezes it expands, wedging the rock apart. The water also aids in the chemical weathering of the rock, so as time goes on the cracks widen, forming the prominent spires.

Moro Rock is best known for the wonderful perspective it provides on the Great Western Divide. The mountains are often hidden from view by other high ridges or thick forest, but Moro Rock stands out from the mountainside, and the view is tremendous.

With the covering of winter snow, one can imagine the glaciers that carved the horns, aretes, and cirques that are so well exposed here. Cirques are the bowl shaped basins on upper ridges where the glaciers accumulated. Aretes are the knife-edged ridges that divide glacially carved valley, and horns are the sharp pointed peaks that result when glaciers pluck rocks from the base of the cliffs in the cirques and aretes. The Matterhorn in the Alps is a familiar example, but there are many horns to choose from on the Great Western Divide.

I have not yet had the privilege, but the High Sierra Trail winds its way from Crescent Meadow in Sequoia to the summit of Mt. Whitney and the Whitney Portal trailhead. It is 60+ miles long, and crosses two major passes, and it must be a marvelous adventure. It is second only to the John Muir/Pacific Crest Trail in popularity.

The picture below illustrates the difference between glacial erosion (the cirques and horns in the upper part of the photo), and the weathering and exfoliation that happens at the lower elevations (the domes both right and left of center).

Moro Rock also provides a wonderful view west towards the Sierra Nevada foothills and the usually invisible Central Valley. You are looking at the most polluted air in the United States: Bakersfield and Fresno. It's not entirely their fault, as they don't necessarily produce more pollution per capita, but the towns are surrounded by high mountains, so they can't blow their pollution into someone else's area the way other municipalities are able to. The photo below is as clear as I've ever seen it from Moro Rock.

Next, we took a look at some trees with a unique geologic history...

Vagabonding across the 39th Parallel: In the Former Realm of Glaciers...Part II, on Trail Ridge

It was the morning of our last day of an all-too-short visit at Rocky Mountain National Park during our vagabonding journey across the 39th parallel. We were now turning towards home, with the intention of crossing the Continental Divide on Trail Ridge Road. It's one of the nation's most spectacular drives, on par with Tioga Pass and Tuolumne Meadows in Yosemite, the Beartooth Highway near Yellowstone National Park, or the Going to the Sun Highway in Glacier National Park. It was another day in the former realm of the glaciers, as we drove from the end of the Pleistocene ice rivers to their source at the Continental Divide.

We made a first stop at Moraine Park to see a non-thunderstorming valley (it had been a wild night in the rain). A turn towards the mountain crest (above) gave us a fine view of a u-shaped valley, and a hanging valley. Hanging valleys develop when a larger glacier cuts a deeper trough than a smaller tributary glacier. The valley floor of the smaller glacier sits at a much higher elevation, often resulting in waterfalls or cascades where the drainage enters the deeper valley. In the picture above, the hanging valley is on the upper right hand corner (click on the photo for a larger view).

Rocky knobs in the middle of the valley that have been shaped by the grinding action of the ice are sometimes called roche moutonnées. The name refers to rock "mutton" or fleece (different sources disagree), presumably because the rocky outcrops looked like grazing sheep from a distance. The ice grinds and smooths one side of the rock, and plucks and tears at the other end, producing an asymmetrical outline.

The linear ridge in the picture above is one of the vast piles of debris left behind along the margins of the glacier that filled this valley, which is called Moraine Park. These ridges are called lateral moraines. A terminal moraine also once blocked the end of the valley, forming a shallow moraine lake. Over time the lake filled with sediment and evolved into the meadow we were strolling along. The picture below provides a perspective on the size of the lateral; it's big.

It was time to start up Trail Ridge, the premier park road that traverses the divide between Big Thompson Canyon and Fall River and crosses three passes, Iceberg, Fall River and Milner, to reach the headwaters of the Colorado River on the west side of the park. The road reaches 12,183 feet (3,713 meters). The route provides a bird's-eye view of the birthplace of the glaciers that scoured the high country.

From our first stop on the road, Many Parks Curve, we had a nice panorama of the lateral moraines we had just left in Moraine Park. The moraines surround the linear meadow in the center of the photo below. The park service website for Rocky Mountain has a marvelous interactive page on the glaciation of the park that offers this particular panorama with labels of the glacial features, and a view of this landscape as it would have appeared during the height of the ices ages.

The road climbs relentlessly and we arrived at the next viewpoint, Rainbow Curve. In the distance on the flank of MacGregor Mountain we could see a feature that is often mistaken for a glacial feature, a group of exfoliation domes (below). It would be easy to imagine glaciers overriding and smoothing off the summit of these granite monoliths, but these peaks stood above the ice rivers. The rounded shape of the domes results from unloading, the expansion of the granite as erosion removes the heavy overlying rock. Cracks form parallel to the surface of the rock, causing corners and edges to fall away.

We were so high up now we might as well have been flying (see the photo below). Looking down we could see the other major glacial moraine complex at Horseshoe Park and the long winding switchbacks of Trail Ridge Road on the right. On the left side one can see the tan colored deposits of the "Alluvial Fan", which formed in 1982 when a poorly built earthen reservoir damming Lawn Lake gave way, pouring nearly 30 million gallons of water down the small side canyon. The surging waters filled Horseshoe Park for a time, and killed three people.

Like Moraine Park, Horseshoe Park was once a shallow lake dammed up behind the terminal moraine of the glacier. When the lake filled with sediment, Fall River flowed across a nearly level surface, and the water took a meandering course across the meadow complex. The meander loops are constantly changing as faster flows cause bank erosion on the outer edge of the loops (cutbanks), and deposition on the inside of the loop (point bar). The loops get larger and larger until they breach the meander neck and form a cutoff.

By the time we reached Forest Canyon overlook, we were truly in the land of glaciers. Looking across the canyon, we had an excellent view of the birthplace of a glacier, a curving bowl-shaped valley called a cirque. The cirque in the picture below is on the flank of Terra Tomah Mountain (12,718 feet; 3,876 meters). Cirques develop when enough snow falls on a yearly basis that some survives the summer melting. Year after year the snow accumulates into a permanent snowbank that has been compressed into solid ice. When the ice reaches sufficient thickness, it behaves plastically and starts to flow slowly away from cliffs, plucking out loose boulders and destabilizing the slopes above. Eventually the ice eats into the mountainside enough to form the bowl-shaped valley.

The snowbanks filling the bottom of the cirque in the picture above are not glaciers; the climate has been too warm these last few centuries to allow a glacier to persist at this elevation. Several small glaciers can be found in Rocky Mountain National Park, and we could see what looked like a small one tucked into a higher cirque in Hayden Canyon (below). The bouldery debris below the icefield can be considered a terminal moraine, although the ridged appearance of the rocks may indicate the presence of a rock glacier, a moving icefield that is more or less completely buried by rocks. The park service site mentioned previously offers an interactive interpretation of the sights seen from the Forest Canyon overlook.

Glaciers in alpine environments tend to form extremely rugged terrain (as seen above), but Trail Ridge Road follows a long ridge with rather muted topography characterized by gentle slopes and swales that were never glaciated.  These boulder-strewn fields preserve a relict landscape of the terrain that existed before the ice age glaciers sculpted the ridges and valleys below.

The conditions are fierce at this elevation, with extreme cold for most of the year, and occasional hurricane-force winds. Trees cannot survive here, the only vegetation being low perennials and grasses that can tolerate the short growing season. This kind of tundra environment is more characteristic of northern Canada and Alaska.

At the highest part of the road we passed a herd of elk relaxing in the sun. Once we crossed Milner Pass, we started descending into the Kawuneeche Valley, the headwaters of the Colorado River. A spectacular ridge forms the western side of the valley, the Never Summer Range. The Never Summers are composed in part of much younger plutonic (granitic) rocks than the ancient metamorphic rocks forming the core of the park. The rocks formed in Cenozoic time (25-30 million years ago) during a time of profound change in the American west. The San Andreas fault was beginning to develop, the Sierra Nevada were beginning to rise, and volcanism was sweeping across Nevada and Utah.

We were considering staying at park's other campground at Timber Creek, which seemed to have plenty of openings for some reason (we were able to stay the previous two nights on the east side only because of cancellations by others). We also noticed that although the views of the Never Summer Range were spectacular, something was terribly wrong with the forest. The trees were dead...everywhere. What happened here? That will be the subject of the next post...