BENEATH THE MOSS: THE OLYMPIC PENINSULA

If you’ve ever set foot on Washington’s Olympic Peninsula, you know it feels like walking into awe inspiring nature—towering evergreens breathing fog, lush moss, and rivers that coil like dragons guarding secrets. 

What most visitors don’t know is that beneath all that soft green wizardry lies one of the wildest geologic patchwork quilts on the continent, stitched together from bits of wandering seafloor, ancient islands, and the sorts of rocks that only a subduction zone could love.

Let’s start with the big mover and shaker: the Juan de Fuca Plate, Earth’s most polite tectonic dinner guest, eternally slipping under North America with the quiet persistence of someone trying not to disturb the table. 

For millions of years, the seafloor has been bulldozed downward, its sediments scraped off, rolled up, smushed, and plastered onto the edge of the continent. 

This collection of recycled deep-ocean debris—sandstones, shales, basalts, the occasional volcano gone rogue—forms the Olympic Subduction Complex, a name that sounds like a niche gymnastics event but is, in fact, the bedrock of the peninsula.

Musashia, Lower Miocene, Clallam Formation

Now here’s where it gets juicy: among all that tectonic tumbleweed lie fossils. Unexpected fossils. Delightful fossils. Fossils that survived a one-way trip toward the mantle and still managed to hang on long enough for you to admire them.

Take the Makah Formation along the peninsula’s rugged northwest edge—a dramatic stretch where Eocene-age marine rocks (think 35–40 million years old) preserve the remains of ancient deep-water creatures. 

Here you can find the ghostly traces of prehistoric whales, fish, and even the occasional bird that took one wrong turn over the Pacific. 

These fossils are often so beautifully preserved that they look like they’ve been waiting under the waves for their close-up. Look at the amazing preservation in the picture perfect gastropod, Musashia, a type of fossil snail or gastropod, belonging to the subgenus Fulgoraria (Musashia) and are part of the larger family Volutidae. The beauty in my hand here is from the Clallam Formation as is the slightly calcified nautiloid, Arturia angustata, though these lovelies are also found in a few other localities along the Olympic Peninsula. 

The Lower Miocene nautiloid Arturia angustata

Adjacent to it lies the Hoshialeah Formation—a rock unit full of deep-sea turbidites, which are basically underwater avalanches that helpfully sorted fine sediments into perfect fossil-pressing layers. 

These rocks carry delicate impressions of fish scales, plankton, and mysterious organic wisps that paleontologists politely argue about at conferences.

Then there’s the Clallam Formation, where 15–20 million-year-old marine fossils swirl through the beds: clams, scallops, barnacles, sea lions, and whales. It’s like stumbling into a Miocene farmers’ market, except everything is stone and nobody is selling artisanal kelp jam.

And we mustn’t forget the Olympic hotshot of insect fossils, the Quinault Formation, which holds rare impressions of long-lost bugs—those six-legged pioneers of ancient Washington who never got the memo about the coming Ice Ages.

Neah Bay, Washington State

All of this—all this turmoil, uplift, squish, scrape, and tectonic origami—has created the spectacular mountains we see today. 

The Olympics are not volcanoes like their shouty cousins to the east. They’re a colossal jumble of once-submerged strata, hoisted skyward by subduction and then sculpted by glaciers into the moody, mist-laden peaks you hike now.

The delightful part? Because the rocks started underwater, much of the peninsula’s geology reads like a deep-sea diary. Even 7,000-foot peaks contain sedimentary layers that formed far offshore. 

Imagine standing on Hurricane Ridge, a mountain meadow full of wildflowers and marmots, knowing the rocks under your boots once lay on a cold ocean floor full of strange fish and drifting plankton. It’s an excellent perspective check—and a great excuse to tell your hiking companions dramatic stories about continental accretion until they pretend they need to stop for granola.

But here’s the real charm of the Olympic Peninsula: the sense of transformation. Every fossil here survived unimaginable pressure, heat, tectonic shoving, and glacial erosion—yet remains as a whisper from worlds long gone. Their presence is a quiet reminder that resilience is baked into the natural world. Even the humblest shell or fish scale becomes, given enough time and a few kilometres of uplift, a monument to endurance.

Whale Vertebrae from Majestic Beach, Washington

If you happen to be wandering the driftwood-strewn beaches near Neah Bay or tracing the tide lines near Clallam Bay, know that you’re standing on the upturned archives of ancient oceans. 

Somewhere beneath your feet, a whale vertebra or clam shell from 20 million years ago is patiently waiting for erosion—and your curiosity—to set it free.

And that, dear fellow rock-romantic, is the Olympic Peninsula: part rainforest, part mountain kingdom, part fossil cabinet, part tectonic balancing act. 

A place where the past is always underfoot, the present is draped in moss, and the future will probably require rain boots.