Posted tagged ‘Metlako Landslide’

Cliff Collapse at Punch Bowl Falls!

May 28, 2018
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Punch Bowl Falls as it once was…

Sometime over the past few months, a huge basalt wall just below iconic Punch Bowl Falls collapsed. Today, a huge debris pile of truck-size boulders have rerouted Eagle Creek and changed this idyllic spot for centuries to come.

The collapse follows a similar basalt wall collapse at Metlako Falls in late 2016, and is another powerful reminder that the spectacular landscape of the Columbia River Gorge continues to be a work in progress, always changing, and never on our terms. We can only react and adapt.

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The great amphitheater at Punch Bowl Falls as it once was…

The news of the collapse comes from a second, major aerial photo assessment in late April by the State of Oregon of the Eagle Creek Burn, the second survey following hundreds of December 2017 images described previously in this article and this article in the WyEast Blog.

A four-person Forest Service crew also reached the scene a few weeks ago, before being turned back by extensive damage to the Eagle Creek Trail. They also reported the massive changes at Punch Bowl Falls as a scene of devastation.

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This sketch shows the approximate area that has now collapsed into Eagle Creek

The collapse at Punch Bowl Falls clearly occurred after the earlier aerial images were captured, as the wall is clearly intact in the December 2017, view, below. With the Eagle Creek Trail closed by the fire and largely impassable to hikers due to debris, it was a stroke of good fortune that nobody was there to be injured or killed — just as the Metlako Falls collapse in late 2016 somehow occurred during the busy Christmas holiday week without harming hikers.

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This December 2017 image clearly shows the west wall (upper left) of the Punchbowl Falls amphitheater still intact (State of Oregon)

This article examines the Punch Bowl collapse in detail from the new images and also includes an update on the Metlako collapse and our first post-fire views of Tunnel Falls.

The Great Mossy Grotto

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“The Grotto” in 2016, with hikers peeking into the entrance to the Punch Bowl

The cathedral-like space below Punch Bowl Falls is known informally as “The Room” or the “Grotto” to hikers, and is the spectacular prelude to the iconic peek into the Punch Bowl, one of the most photographed scenes in the world. The massive space begins at Lower Punch Bowl Falls and leads to the narrow entrance to the Punch Bowl, proper.

On a typical summer day in years passed, the cobble beach at the Grotto was filled with hikers soaking feet in the cold water of Eagle Creek, stacking stones and wading into the creek for photos of Punch Bowl Falls — a necessary commitment to photographing the falls during much of the year, and part of what made the trip so memorable.

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The Punch Bowl cliff collapse of 2018 (State of Oregon)

The cliff collapse has changed all of this. A 300-foot section of the sheer, 150-foot high wall that formed the west side of the Grotto calved off, leaving a huge bench of debris in what used to be the main channel of Eagle Creek (shown in the annotated photo, above).

A closer look at the debris pile (below) shows roughly a dozen giant basalt slabs that survived the collapse intact. Their closely fitted position — like pieces in a basalt jigsaw puzzle — also suggests that the wall calved off as one huge slab, tipping over like a domino before breaking apart where it landed in Eagle Creek.

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The former cliff wall now resides flat, like pieces in a jigsaw puzzle (State of Oregon)

This look (below) at the debris pile shows one of the larger boulders (in the upper left) sitting squarely in the narrow entrance to the Punch Bowl. Depending on your aesthetic, this boulder will block the classic view of Punch Bowl Falls, provide an interesting foreground once covered in moss and ferns — or, perhaps, provide the ultimate viewpoint? But the view here has clearly been changed forever.

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These giant boulders landed in one of the most photographed scenes in the world… (State of Oregon)

This annotated “before” view of Punch Bowl Falls gives a sense of where the large new boulder (and a few smaller boulders) rests:

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A large, new boulder sits here — and is approximately the same height as the rounded, fern-covered rocks on the right in this “before” view.

This close view (below) focuses on the boulders that now reside in the entrance to the Punch Bowl. At the time of the collapse, it’s likely that Eagle Creek was completely dammed behind the new debris, and quickly carved a new channel around the east edge of the landslide (in the lower right corner).

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Eagle Creek made quick work of a debris pile that almost certainly plugged the outlet to the Punch Bowl, forming the new channel in the lower right in this view (State of Oregon)

This close view (below) shows more detail of the series of horizontal slabs that make up the debris pile, with Eagle Creek turning abruptly to the east in its new channel. It’s likely that the “viewpoint” boulder sitting in the entrance to the Punch Bowl was originally connected to the rest of the debris pile following the collapse, with the stream carving channels on both sides of the rock as it found a new path past the debris.

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Reaching the new “viewpoint” boulder (shown with logs lying across it) could be challenging during the wet months (State of Oregon)

The large, blocky boulder tipped on edge near the left side of the above photo looks large enough to block the creek from further eroding the west  side of the debris pile (below the new cliff face) in the near future. If so, Eagle Creek may have already found its permanent channel around the new terrain.

Eagle Creek is a powerful stream that cannot be safely forded for much of the year. If this is the “new” main channel, with a vertical cliff on one side and a couple of garage-size boulders on the other, the new land created by the debris pile will only be accessible during the low water months of late summer. This could be a good thing if it means fewer boots and flip-flops on the new terrain as it slowly recovers — though frustrating to visitors hoping for a look into the Punch Bowl.

This more vertical perspective (below) shows all of the pieces in context — Punch Bowl Falls in the extreme upper left corner, the new debris pile and fresh cliff scarp on the right, re-routed Eagle Creek in the center and Lower Punch Bowl Falls at the bottom center:

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Big changes at Punch Bowl Falls (State of Oregon)

[click here for a very large version of the above photo]

This even closer, annotated version (below) shows the new features in detail:

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The Punch Bowl cliff collapse in detail (State of Oregon)

As jarring as these changes to Punch Bowl Falls may be to look at, there’s (hopefully) some comfort in knowing this is simply part of the geologic process that continues to make the Columbia River Gorge such a unique and exceptionally beautiful place.

Consider that exactly 45 years ago, a similar, somewhat larger collapse occurred at Tanner Creek, the next drainage to the west of Eagle Creek. Today’s Wahclella Falls trail meanders through the still-fresh looking landslide there, and like the collapse at Eagle Creek, huge basalt slabs survived collapse at Tanner Creek intact.

In fact, the Tanner Creek canyon below Wahclella Falls is littered with giant basalt reminders that the steep cliffs of the Gorge are in a continual state of erosion, though in our short life spans these events seem rare. Each of the the dramatic, moss-covered boulders in this view of Wahclella Falls (below) tells a story much like the one unfolding at Eagle Creek.

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The long history of landslides at Wahclella Falls is on full display with dozens of truck and house-sized basalt boulders crowding Tanner Creek

The cliff collapse at Punch Bowl Falls follows the same storyline, with Eagle Creek carving a new channel through the debris, removing smaller material in the process, and leaving the larger, solid blocks of basalt in place. The annotated photo (below) shows how the new channel and debris pile will appear at stream level, from the foot of the Lower Punch Bowl trail — once hikers are allowed to return here:

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Approximate location of the new Eagle Creek channel through the Grotto

This annotated panoramic view (below) of Punch Bowl Falls and the Grotto wall before the collapse shows the extent of the cliff that has dropped away. As the photo shows, Eagle Creek had significantly undercut the cliff, leaving an overhang 10-15 feet deep that was likely the main cause of the eventual cliff collapse.

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Panoramic view of Punch Bowl Falls (left) and the Grotto wall overhang before the collapse

The overhang along the Grotto wall at Eagle Creek had much in common with another recent collapse that occurred in Oregon’s Coast Range. At Drift Creek Falls, a similarly undercut basalt wall (below) abruptly dropped into the creek, exploding into a large debris pile and a few large, intact slabs of the former cliff face. Like Eagle Creek, the Drift Creek trail happened to be closed for construction at the time of the collapse, preventing what might have been a human tragedy on this very popular trail.

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Drift Creek Falls before the 2010 cliff collapse (Photo by Greg Lief)

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Drift Creek Falls immediately after the 2010 cliff collapse (U.S. Forest Service)

A series of views looking downstream at the Punch Bowl cliff collapse round out the new images captured by the State of Oregon. The view below shows a clearly “overfilled” Punch Bowl, raised a few feet from its previous level by the new debris pile, downstream. This annotated view also shows the Punch Bowl overlook along the Eagle Creek Trail.

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Downstream perspective on the big changes that have come to Punch Bowl Falls (State of Oregon)

This is a somewhat closer look at the Punch Bowl and debris pile, looking downstream:

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Downstream view of the Punch Bowl and debris pile now blocking the lower entrance (State of Oregon)

This annotated view (below) shows the narrow entrance to the Punch Bowl, now blocked by the new “viewing” boulders, with the debris pile and new cliff scarp, beyond:

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View of the entrance to the Punch Bowl and the new debris pile and cliff scarp (State of Oregon)

This very close view (below) of the “viewing” boulders shows a fair amount of debris under the surface of the Punch Bowl pool, and the beginning of what will almost certainly be a substantial log pile at this location:

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Close-up of the new “viewing” boulders that landed in the entrance to the Punch Bowl on Eagle Creek (State of Oregon)

Forest Service officials surveying the impact of the Eagle Creek Burn linked the cliff collapse at Punch Bowl Falls to the fire, and it’s true that many of the burned slopes of the Gorge have been experienced severe erosion and landslides since the fire. But a similar collapse happened just downstream at Metlako Falls, before the fire, showing these dramatic events to simply be part of the ongoing shaping of the Columbia River Gorge.

As shown previously, the basalt wall in the Grotto at Punch Bowl Falls had already been significantly undercut by Eagle Creek over centuries, and was ripe for collapse. If the fire had an effect, it’s most likely that increased runoff from burned slopes sped up the inevitable by seeping into cracks that were already forming in the cliff, and triggering the event.

If this is true, then we may see more cliff collapses in the Gorge in coming years — but rather than being caused by the fire, they represent part of an ongoing process in the Gorge that conditions like heavy rain events, runoff from burned areas, extended freezes or even seismic events (the theory behind the ancient Bridge of the Gods landslide!) can trigger.

More Metlako Collapse Images

The new aerial series of the Eagle Creek Burn provides more views of the 2016 cliff collapse at Metlako Falls. In the five months since the first series of photos were captured, Eagle Creek has continued to carve away at the debris pile dam. Logs from the fire are also already entering Eagle Creek in large quantities, and dozens more were stacked on the Metlako debris pile over the winter, doubling the size of the logjam just since December.

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Eagle Creek has been busy stacking logs on the new debris pile below Metlako Falls (State of Oregon)

A closer look (below) at the debris pile shows a difference in how this cliff came down compared to the more recent collapse at Punch Bowl. While the wall at Punch Bowl appears to have tipped forward and crashed face-down into Eagle Creek, the collapse at Metlako appears to have slipped down vertically, partly intact. This is suggested by the large basalt slab holding back the logjam, where the weathered, mossy former face of the cliff is facing up on this huge remnant.

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Close of view of the huge log pile on top of the Metlako Falls debris pile, and the dam that still backs up Eagle Creek (State of Oregon)

While the Punch Bowl cliff collapse involved the entire vertical face of the cliff, a closer look at Metlako collapse shows that an upper layer of basalt split off, landing in front of a largely intact, lower basalt layer. The annotated view below shows the newly exposed rock face of the upper basalt layer and the clear break between the two layers of basalt. This might explain why the rock slipped into the canyon here, as opposed to tipping over and landing face down, like the Punch Bowl collapse.

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The Metlako collapse appears to have slipped in, not tipped over (State of Oregon)

[click here for a very large version of the above photo]

The above view also suggests that similar collapses have occurred downstream along this section of the Metlako gorge (to the left, in the photo) and went unnoticed — perhaps because this adjacent area was out of view from the former Metlako spur trail and viewpoint. The moss layer on the cliff face in the downstream area show this collapse to have occurred prior to the December 2016 event, while the still raw debris pile below this adjacent cliff face suggest it was still a relatively recent collapse.

In both cases, the presence of underground springs suddenly emerging at the new cliff scarp as a pair of waterfalls suggests a lot of water flowing between the basalt layers in this cliff section, destabilizing the upper basalt layer until it finally collapsed under its own weight.

Finally, Tunnel Falls Images

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Our first look at Tunnel Falls shows a heavily burned landscape (State of Oregon)

[click here for a very large version of the above photo]

Finally, the new State of Oregon images give us a look at Tunnel Falls, on Eagle Creek, a spot that was missed in the December images. While much of the lower portion of the Eagle Creek canyon was moderately burned in the fire, the area around Tunnel Falls appears to be more severely affected.

While the slope above the falls appear heavily burned, the protected canyon at the base of the falls (below) appears to have experienced more of a mosaic burn, with several large conifers surviving the fire. This bodes well for a rapid recovery of the riparian corridor along this part of Eagle Creek.

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Several large trees along the East Fork survived the fire in a “mosaic” burn pattern (State of Oregon)

Before the Eagle Creek Fire started in September 2017, an earlier blaze called the Indian Creek Fire had been burning for weeks in the headwaters of Eagle Creek, on the slopes of Indian Mountain. These fires merged soon after the Eagle Creek fire erupted. The new State of Oregon images provide the first look at the Indian Creek area, and show an extensively burned landscape with the forest mostly killed by the fire.

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Indian Mountain is badly burned in the headwaters of Eagle Creek (State of Oregon)

As recently as the early 1980s, the upper slopes of nearby Tanner Butte were still largely open meadows, and recovering from fires that burned there in the early 1900s. Today, dense beargrass still lines the trail to Tanner Butte, a remnant of when beargrass and huckleberry meadows that once covered the butte, and scattered conifers that became today’s forests were just taking hold.

The northern slopes of Indian Mountain (in the distance in the above view) are still recovering from the same early 1900s fire that burned Tanner Butte, and still consist of mostly open beargrass meadows and a scattering of stunted subalpine trees.

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Detailed look at the severe burn that occurred along the slopes of Indian Mountain, at the headwaters of Eagle Creek (State of Oregon)

As the new Eagle Creek Burn moves into recovery, we’re likely to see a similar landscape emerge on the high ridges here over the coming decades. Lower, wetter slopes will initially recover with thickets of red alder, vine maple and other deciduous trees before conifer forests once again become established. The dry, upper slopes will take much longer, with beargrass and huckleberries as the first pioneers.

This new burn will take decades to recover, but because it is protected as wilderness, it will also provide a unique opportunity to study a western Cascade forest recovery as nature intended, without human intervention.

Making peace with the changed landscape…

Sometimes when it rains, it pours. In the span of just over a year, the landscape of our beloved Eagle Creek, a place that is nothing short of a temple to so many, has radically changed. The collapse of the idyllic viewpoint of Metlako Falls in December 2016 was shocking, and the human-caused Eagle Creek Fire still seems surreal to those who consider the Gorge their refuge from the everyday stresses of life.

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Punchbowl Falls in the early 1900s, when piles of gravel released from turn-of-the-century fires filled the bowl

The first set of aerials after the fire had some good news — Punch Bowl Falls had dodged the worst of the fire! But now the recent cliff collapse at Punch Bowl has forever changed a spot that is perhaps most sacred to those who love the Gorge. It’s still hard to absorb the reality of these events, even as we study the images.

I wrote this article with an eye toward describing and understanding the natural history of these events, and hopefully in a way that also respects the emotional ties that so many have to Eagle Creek and Punch Bowl Falls. I share that sense of loss and sadness at these changes, too.

It will be awhile before hikers are allowed back into the Punch Bowl Falls area. The Eagle Creek trail has been heavily impacted by loose debris and falling trees from the fire, and the wall collapse at the Punch Bowl will almost certainly be closed to the public until the terrain has stabilized. More changes are likely, too — inevitable, in fact— as the area continues to recover.

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The Tanner Creek collapse in the spring of 1986, just 13 years after the massive landslide occurred. Today’s loop trail crosses the base of the landslide, and the landslide has become part of the landscape.

I was just eleven years old when the collapse at Wahclella Falls briefly dammed Tanner Creek and forever changed that area. While it was shocking to see the aftermath, over time the landscape has begun to recover. Just 20 years after the collapse, the new (modern) trail through the landslide was built, and today the giant boulder garden created along Tanner Creek is part of the awesome beauty and spectacle of the area. I look forward to watching a similar recovery at Eagle Creek — and hopefully I’ll live long enough to see the newly created landscape wrapped in moss and ferns, and framed by young stands of Bigleaf maple and Western red cedar!

We’re so fortunate to live in a place where the natural landscape is still under construction, though it does require us to take a longer view to adapt to the big changes that inevitably occur. The recovery will take years, so finding peace in witnessing and understanding the awesome natural processes at work is my own refuge for coping with the changes.

I hope you can find some refuge there, too.

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Editor’s note: for the first time since starting this blog in the fall of 2008, I fell behind my usual pace of posting at least monthly, as I’ve been tending to some challenging family needs. But I do have a nice backlog of topics and will hopefully make up for lost time over the next few months!

As always, thanks for taking the time to stop by!

Tom Kloster • May 2018