May 4, 2025
Olympic peninsula, Washington
On our latest trip out to the Olympic peninsula we hiked four beaches. The Rialto Beach day was pouring rain and strong wind — that happens. The First Beach days (by La Push) were about Gray whales, grandkids and driftwood forts. The Second Beach day was for a long hike at extreme low tide with the grandkids down to the sea cave.
On our last day we decided to hike down to Third Beach. It had been quite a few years since it’s a fairly strenuous trail for oldsters like us. Besides being less frequented than the other beaches and with a great view of the Giants Graveyard seastacks, I wanted to see what a particular landslide site currently looks like. Landslides are not uncommon along this coastline but the one we saw in December 2013 was very fresh and it’s been interesting to watch the changes.
There are far fewer parking spaces available for the Third Beach trailhead compared to the more easily accessed Second Beach and Rialto. A good number of the people who park there are doing multi-day backpacking trips so those cars stay for days. The Third Beach trail provides the only access to the 20 miles of Olympic National Park coastline southward, a “trail” that includes sandy and cobbly beaches, creeks to ford, headlands to round (at low tide) and impassable headlands to climb over, not an easy hike. Luckily we were there in early May, before things get too crowded along this coastline. And indeed once down on the beach there were only a few people there, which gives a place a very different vibe.
The end of the trail descends onto Third Beach paralleling a big creek gully.
Creek gully on the left. Tree roots on the right are the steps much of the way, down 150 vertical feet
All this driftwood came from what got washed down the gully over the years.
That looks like a lot of driftwood but the pile is actually considerably smaller than it used to be in decades past. Back then you had to crawl over it to get from the trail to the beach but this time we just skirted it on the right.
Driftwood accumulations have been declining on the Washington coastline, mainly due to fewer trees inland. For the most part, driftwood originates from trees falling in forests and being carried down to the coast in winter by flooding creeks and rivers. Since the late 1800s, the logging industry has taken out nearly all the old growth trees between the coast and the highest elevations. On the Olympic peninsula large open swathes of clearcut are visible anywhere not within National Park acreage. The driftwood we see on the beach is mostly legacy, especially the big ones. A study in nearby Puget Sound quantified that.
In one of the few studies to look at the function and characteristics of local driftwood, UW graduate student Daniel Tonnes tagged and carbon-dated logs at eight Puget Sound beaches. He found that more than 90 percent of the larger logs died between 90 and 300 years earlier, with the majority dying pre-1850. Seattle Times
Gradually driftwood gets lifted by winter surf and transported to other spots on the coast. But this mass of driftwood has been getting smaller over the past decades, like the coastline in general. Without fresh downed trees inland to wash down creeks and rivers, driftwood declines.
The trailhead and creek gully are about half way along the beach. You can either go north to Teawhit head or south to Taylor point. We chose to walk south. The landslide site is most of the way down the beach that way.
Geologically, all the Olympic peninsula is a mishmash of rocks formed 20 million years ago or so at the bottom of the sea and pushed up by plate tectonic forces from the west. Fault lines, upside down and twisted bedrock, unconformities, and huge contrasts in rock type abound. In general, the headlands and seastacks are composed of very hard sandstone and conglomerate while the bedrock behind the beaches is made up of tectonically weakened “melange”. Melange is more easily eroded, hence the carved out shape of the beaches.
Blue arrow points to Third Beach. From Washington Department of Natural Resources, Coastal Geology between Hoh and Quillayute rivers, page 20
Mostly, the coastline in this area looks fairly flat, up 100-200 feet. That’s a wave-cut terrace from a time when the land wasn’t as uplifted as it is now. On top of that terrace are several layers of Pleistocene sediment washed down from the mountains during the Ice Ages in the past million years.
Landslides are common where the bedrock is weaker. When a slope gives way it carries dirt and vegetation as well as boulders.
A scar remains visible high up on the bluff. That yellow zone is actually windblown sediment dated to 8000 years ago. The boulders on the beach provide good markers for comparison.
Here’s what the landslide site looked like a couple of weeks ago, viewed from the south:
May 4, 2025
For comparison, here’s what it looked like a little more than a decade ago:
December 2013. Note the trees, rubble and dirt are covering the boulders, and that the still-anchored alders are tipped sideways. For scale, that’s me standing at the exact center of this image, in blue.
It’s clear a decade has changed the site. Most of the dirt and giant trees that slid down the hillside have been washed away by winter storms. The boulders are now completely uncovered of dirt. And the hillside has grown up in fresh alders. There were multiple landslides at this spot for a few years after the one in 2013 but the slope appears fairly stable for the moment, although some of the alder trunks don’t look completely vertical. I wrote up a bucket about this site back in 2016 which has lots more pictures and explanation (The Daily Bucket - landslides keep sliding (an Olympic Peninsula case study).
Trees, shrubs and wildflowers have colonized the new slope face. The red flowered plant is Paintbrush (Castilleja).
Third Beach ends at Taylor Point. It is impossible to go around even on the lowest tide so to continue on south you have to climb up and down a series of rope ladders to get over the headland to the beaches, creeks and seastacks beyond. We turned around here.
Taylor Point and the Graveyard of the Giants. Nice waterfall where the sand ends, a hanging valley.
The Giant’s Graveyard, like all seastacks, are composed of more resistant rock than most coastal bedrock. They used to be part of the land. Over the past several million years erosion has been carving into the coastline and they have been left behind for a bit longer before they too wear away. Given my ephemeral lifespan, I won’t see that. But I can observe changes like landslides and driftwood.
🌊
Partly cloudy and continued dry today in the PNW islands. Temps are seasonable. Precipitation is still well below normal for this water year.
What’s up in nature in your neighborhood?
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