Whispers and Echoes from the Past, When Half My DNA Visited Yosemite National Park

While my "Vagabonding on Dangerous Ground" journey took me far north of my usual haunts in the Sierra Nevada, I had an unexpected encounter with Yosemite National Park while I was gone. We had a brief visit with my mom as we drove home from our long trip. While there, I saw an ancient looking leather booklet, one of those little photo/scrapbooks that were popular in the days when pictures were printed on paper. It was full of pictures of half my DNA visiting Yosemite National Park in the early 1940s. My love for Yosemite is literally in my blood!

The "half DNA" of course was my mother when she was just a few years old. As I flipped through the photographs, I realized that I have been standing in these same places, snapping pictures of my own. It was possible to put them side by side. I wondered to myself, how has Yosemite changed in those 73 years? And more importantly, how has Yosemite NOT changed?

The most noticeable difference is the vegetation. Trees that are in some pictures aren't in others. That's not much of a surprise, given the fact that many trees can grow to maturity in that time period. The man-made structures underwent changes as well. The Tunnel View Parking Lot (in the top picture) was completely renovated and rebuilt just a few years ago. The "Swinging Bridge" at the Swinging Bridge Picnic Area (below) no longer swings. It was replaced by a more stable pedestrian bridge a couple of years ago. The cute little girl on the left in the picture is mom.

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Other changes are more subtle, at least in slightly fuzzy photographs from nearly three quarters of a century ago. A number of serious geologic events have taken place, including three or four of the biggest rockfalls and debris avalanches ever witnessed in the park. I even witnessed one of them, when a large slab came off the face of El Capitan in 2010. The Ahwiyah Point rock fall in 2009 permanently changed the appearance of Half Dome, and the 1996 Happy Isles rock fall did the same to the cliffs below Glacier Point. Four "hundred-year" floods scoured the river channels in the valley in the last 50 years or so, washing away buildings and camp facilities.

The things that didn't change are the things I realized were important. Yosemite National Park is a treasure, and the idea of preserving it for future generations was America's best idea, as the Ken Burns documentary pointed out in beautiful fashion. In one sense, Yosemite is where it all started. In 1864, Abraham Lincoln gave Yosemite Valley to the state of California, with the idea that it be preserved in perpetuity. Later, in 1872, Yellowstone became the first official national park, and Yosemite followed in 1890. The idea of protection and preservation moved forward in fits and starts, with some failures and other hard fought victories. Hetch Hetchy Valley, the second "Yosemite" in the park, was inundated under the waters of a reservoir in 1923. But the ridiculous idea of building a tramway to Glacier Point was stopped cold in the 1970s. The totally crowd-pleasing, but totally unnatural nightly firefall ended in 1968. As I looked through these ghostly pictures of the past, I realized that I've been able to experience the park much as my family did all those years ago. The park has changed, but for the most part the change as been directed towards an appreciation for the natural environment, and not towards profit-making opportunities (although that happens).

My grandparents took my mother to Yosemite in a time and in circumstances that were difficult. It wasn't that the park was inaccessible. The "All-Weather Highway" (Highway 140) was completed in 1926, and other good routes were available. But with the war going on, resources were limited. In those days it would have been quite the challenge for a family of modest means to find their way to the park from Southern California. Although it costs more these days to enter the park, one can stay in relatively inexpensive campgrounds and still have an affordable experience in one of the most spectacular landscapes on the planet. The park can be very crowded at times, but those who are willing to walk a bit can find absolute solitude in the 95% of the park that is officially wilderness land.

Yosemite National Park remains a wonderful place, despite budget constraints and government neglect. The rangers, park personnel, and volunteers do the best they can with the resources they are given. The idea of national parks is still America's best idea, and the parks deserve our vigilance. Threats from those who would profit from our most beautiful landscapes should be stopped, and that's only going to happen if those of us who love the parks keep the pressure on our political representatives. It's never easy, but it needs to be done. I want my pictures of today to compare favorably with the three dimensional total sense immersion photographs and virtual reality images that will be taken by my grandchildren 75 years from now.

If you want to be involved, join the Yosemite Conservancy. Most national parks have a natural history association that fights for the good of the parklands. They deserve your support as well.

Two Serene Hours in a Very Noisy Place: The North Valley Trail in Yosemite Valley

Yosemite Valley is an awe-inducing place, a place that was the inspiration for my current series on "What are the Most Incredible Places You've ever Stood"? I've been there many times and I never get tired of it. It is a destination for three of my field trips every year. It is an easy thing to drag a bunch of students up there (you make it required and stuff them on a bus), but how does one get past the sheer elegance of the scenery and explain to students the grandeur of the geological story of Yosemite as well? Part of it is letting them find out for themselves.

It's a bit of a trick to take 40 students to Yosemite on a busy Saturday in May. Buses are allowed to park in only two or three spots in the valley, and an extended discussion of geology is not possible in a place like the Wawona Tunnel View (above and below). It's simply too crowded with noisy buses and motorcycles and hundreds of tourists enjoying a first view of the valley, and it's really not fair to have a bus parked there hogging a premium spot. So we park the bus at Yosemite Lodge, and I set them free to wander through the park...to an extent. We make appointments. They find their way through the valley floor on the free trams, and we meet each other at a few of the most important localities (principally the Happy Isles rockfall site and a vantage point where we can talk about Half Dome and Yosemite Falls). It works well most of the time because they get a sense of exploration to go with the "learning".

I like the schedule for a different reason. The students have about two hours to find the visitor center and make a series of observations while making their way through the tram system to the other end of the valley. That's two hours that I can use to make some observations of my own, along with a bit of exploration. The trams are great, but nothing can compare with walking the length of Yosemite Valley on one of the less busy valley trails. Two hours of brisk walking for me equates to about six miles. I headed up the trail to Lower Yosemite Falls, trying to make my way through hordes of tourists (and a fair number of my students headed the same direction). It was crowded and noisy, but only a few hundred yards further I had the trail largely to myself.

 The North Valley Trail follows the base of the cliffs above the roads and valley developments. It is surprisingly quiet; I couldn't hear the traffic far below, only the breeze through the conifers and pleasant song of a bird I couldn't see or identify.

I soon passed a superb example of a talus slope at the base of Yosemite Point. In many places the cliffs of Yosemite are bold and vertical, but in other places there are recessed coves with extensive slopes of fallen rocks. The difference lies in the pattern of jointing in the rock. Granitic rocks form deep in the crust miles below the surface under great pressure. As they are exposed by erosion, the rocks expand and fracture. The composition of the rock seems to determine the spacing of the joints, and when they are far apart, bold cliffs occur. When they are closely spaced, rock falls are common and talus slopes are the result.

The trail climbs several hundred feet above the valley floor, offering views in both directions. Across the valley stands Sentinel Rock, one of the most imposing cliffs in Yosemite (although it sometimes gets lost in the scenery, being located across the valley from Yosemite Falls). On the other side are the cliffs of the Three Brothers. The cliffs that make the three brothers are more easily seen from the other side, but from my vantage point I could see the scar of the 1987 Three Brothers rockslide, which dumped something like 600,000 cubic yards of debris onto the valley floor. Luckily no one was hurt, since the park service had some warning that a big slide was imminent and closed the road at the base of the cliff. It was the largest mass wasting event in the recorded history of the valley.

John Muir and other earlier visitors remarked on the open park-like aspect of the woodlands on the valley floor. Fire suppression since the establishment of the park in 1890 has allowed the growth of a thick forest across most of the valley, but below the Royal Arches and Washington Column there are some beautiful old oaks that recall the original state of the valley at the time it was discovered by Europeans (the Miwoks and other first nation people have known of the valley for thousands of years).

Half Dome soon became visible as I worked my way towards Mirror Lake.

 The Dogwoods were still blooming along the side of the trail.

After three or four miles of walking I arrived at Mirror Lake. The "lake" is more of a wide spot in Tenaya Creek that developed as a result of a gigantic landslide in prehistoric time. The creek formed a series of ponds behind the rockslide that in springtime reflect the surrounding cliffs, especially Mt. Watkins and Half Dome. By summer Tenaya Creek often runs dry (especially this year with the drought conditions). On Saturday it was beautiful, but also crowded. I set off towards Happy Isles and soon left the crowds behind.

Half Dome from the vantage point of Mirror Lake is the very definition of "looming". It is nearly 4,000 feet of steep cliffs. Another major mass wasting event took place near here in 2009, the Ahwiyah Point rockfall. It involved something like 115,000 tons of granitic rock. Luckily it happened early in the morning and no one was hurt.

The small details are easy to miss in a crush of people. I enjoyed some more Dogwood flowers...

...and the hard work of huge bumblebee in the Lupine blooms.

After I met with the students at Happy Isles, we started making our way back to Yosemite Lodge. I took one look at the packed tram, and decided it would be nicer to walk back. The direct route was two or three miles, and I had a fair chance of beating the tram (the dozen or so stops and the heavy traffic made for a slow motorized journey). Along the way I was thrilled to see a White-headed Woodpecker for the first time.

Our final stop was in a meadow at the base of Yosemite Falls. It provided an outstanding view of Half Dome where we could discuss the origin of the iconic feature. Soon after we were back on the bus and headed home. It was a spectacular day!

How it was: The Last Days of Fall in Yosemite

We were in Yosemite last weekend, catching the last vestiges of the fall season, and exploring a landscape that was at the end of a cycle. Life was ebbing, preparing for the arrival of winter, which apparently intends to arrive on Thursday (a series of snowstorms is expected). As such, we were probably some of the last people who got to visit Glacier Point this year. It was a beautiful day (I would be more poetic about it, but words start to fail when trying to describe a place like this).

The peak of the fall colors was some time ago. We passed groves of trees that had lost all their leaves, but in some sections of the park, color was still intense. I understand that the eastern hardwood forests are the epitome of fall glory, but I also see wonder in catching the colors spread out in a dark conifer forest as the sun lights up the dogwood and oak understory.

 A spider was feverishly busy trying to catch a last meal for the season.

There were a few flowers still hanging on near the Merced River. This apparently is a Coneflower (my credentials as a biologist have always been suspect). The flowers were on their way out; the petals were gone on the other side of this one.

The Merced River was running slow and clear. Last spring I would have been standing in two or three feet of water at this spot.

We headed up the road to Glacier Point. The air was still and clear, and there were no clouds. The peaks stood out clear as crystal, and I couldn't help taking pictures of mountains and domes I've photographed many times before. It always seems like I am looking for unusual lighting and clouds to spice up pictures of these features, but today I was concentrating on preserving the peaks in plain afternoon sunlight. The pictures make me think of a baseline, a version from which all other pictures can be compared ("what do those mountains look like when they aren't shrouded in mysterious clouds?"). The exfoliation dome of Mt. Starr King appears below.

The Sierra Crest could be glimpsed in the distance, with Mt. Lyell, the highest peak in the park at 13,114 feet (3,997 meters) barely visible. Peaks of the Clark Range a little west of the crest tend to dominate the skyline. A few small patches of snow made it through the summer.

Half Dome sits across the valley from Washburn and Glacier Points. A zoom on the summit revealed no hikers; I'm guessing the cables are down by now, so no one was around.

Mt. Clark is a pretty nice example of a glacial horn, a peak that has been steepened on all sides by the plucking action of the glaciers that were here only 12,000-13,000 years ago.

I was reminded while looking at Tenaya Canyon below Half Dome how much geology changes the park. If you remember this view from any time before 2009, it is forever changed now. The Ahwiyah Point rockfall produced the long white scar down the slope in the center-left side of the photo. It was the biggest rockslide in more than two decades.

Glacier Point offers one of the greatest views to be seen anywhere. The cliffs drop 3,000 feet below one's feet, and there is a unique perspective of the famous waterfalls, since they are being observed from above. Yosemite Falls had the smallest of trickles falling down the face (the bright sunlit cliff). In a few days ice will replace water on the cliff face.

On the way down Glacier Point road, we stopped for a look at Summit Meadow. The willows had turned red, contrasting with the yellow meadow grasses and the evergreen lodgepoles. To get the reflections on water, I had to get out into the middle of the meadow, which is not really a nice thing to do, since the trampled grass and mud is unsightly, and it damages the soils. So I found a way to get there without stepping on grass...

 And there it is, a fallen tree. It was a real balancing act to not fall off.

And that's the way it was. I saw reports that it was very windy in the valley today, and that snow level will be down to 3,500 feet or so by the end of the week. Yosemite will be a very different place by the weekend.

Half Dome is down to a Quarter! Will Anyone Want to Visit Yosemite?

OK, not really, I'm just continuing a brief series on Yosemite Valley encouraging folks to look behind and to the side of the iconic features like Half Dome, El Capitan, Yosemite Falls and Bridalveil Fall. Our "high-water journey" to Yosemite Valley last week included an excursion to Glacier Point, which had opened to visitors only a few days prior.

The views from Glacier Point, and the usually quieter Washburn Point, were spectacular, as they almost always are. Half Dome dominates the views, so I was trying to take a few shots that didn't have the granite monolith in the center. They appear below.

I am always struck by the grandeur of Tenaya Canyon, the main tributary valley to the Merced River that meets the Merced at the head of Yosemite Valley. I call it a tributary "valley" because Tenaya Creek is a relatively underfit stream, quite incapable of carving such a deep valley, one that rivals the Grand Canyon in depth.

Even the glaciers shouldn't have been big enough to carve such an impressive gorge, and they wouldn't have except that the vast ice sheet that covered the Tuolumne Meadows area to the north spilled over and contributed a vast amount of ice to the otherwise small Tenaya glacier system.
It was a week of the highest snow runoff, with the Merced River running at 7,000 cubic feet per second, about three times normal. So with a zoom shot, I was able to spy the rarely viewed Pywiack Cascades, in a trailless and inaccessible part of Tenaya Creek Canyon (an interesting description of the high adventure journey through this gorge can be found here). I would love to make that journey, but I'm getting just a bit old for such ventures!

If Half Dome didn't exist, North Dome and Basket Dome would certainly command more attention. Unlike Half Dome, these lower domes were probably covered by ice during the most intense glaciations, but in the last 800,000 years most of the shaping has been accomplished by exfoliation. Exfoliation is a form of unloading, in which the granite expands as it is exposed by erosion, cracking into slabs running parallel to the surface of the rock. The slabbing tends to break off corners and edges, leading to the characteristic dome shape.

The view from Glacier Point changed forever in March of 2009 when a huge rockfall, the biggest in two decades, thundered off of Ahwiyah Point below the cliffs of Half Dome. The light colored strip running across the photo above shows the path of the slab, and the pile of talus in the shadow shows the impact point. Hundreds of trees were blown down, and a popular hiking trail was covered, but luckily no one was hurt.

I know it is hard to see the view from Glacier and Washburn without actually noticing Half Dome, and so I did take quite a few pictures of it. One of them is below, if you are feeling only half-satisfied by the rest of the post!

Ahwiyah Point Rock Fall Update: Before and After Photos

Now that the Glacier Point Road is open, Yosemite National Park visitors have an opportunity to get a true bird's-eye view of the Ahwiyah Point rock fall that took place in late March of this year. This was an event that changed the look of Yosemite Valley forever, and drives home the point of the rate of geologic change, even on a human time scale.

Many thanks to Doug Nelson, photographer of the image of the slide, taken a few days ago. The top photo was from a 2005 visit to Glacier Point by my field studies class.