Smith Rock Hike: Volcanic rocks, volcanic heat

Although we’ve lived in different time zones for a while now, my sister Heather and I have been lucky enough to be able to go camping and hiking together once a year… and we kept up the tradition when she visited me in Oregon!

We set our sights on some classic Oregon landmarks that I hadn’t visited yet either: Smith Rock, South Sister, and Crater Lake.

twin trip locations

Map background from MapBox.com

Fun sights between Corvallis and Bend… Mt. Washington and a very festive Sinclair dino in Sisters.

While this was technically a camping trip we copped out and stayed in a hostel in Bend for the first night – Bunk & Brew – which made up for its scarcity of showers by offering complementary local craft beer. This splurge was totally justifiable because it enabled us to get up at the crack of dawn to beat the crowds to some crazy geology.

26.5 million years ago a massive volcano blew its top in central Oregon, spewing enough ash to enough to cover the state of Texas in a layer about 2 meters thick. The Crooked River Caldera eruption would have been catastrophic for any living thing in the area… just check out the phenomenal remains in the nearby John Day Fossil beds. However it was a boon for modern climbers, because it created the foundation of Smith Rock State Park!John Day Formation

The figure above shows the extent of the Crooked River Caldera (red shape #1) and the two other small eruptions that created the John Day formation, including the Smith Rock Tuff. However the rest of the region’s tuff deposits form low hills, not huge towers – why is Smith Rock so different? It turns out that location is key. Because the park lies within the original caldera, shortly after the tuff was deposited super-heated water carrying dissolved minerals rose up through it. This cemented the tuff much like dilute glue would stiffen sand, combining the best of both worlds for climbing – the funky irregular texture of tuff and the hardness of a sandstone.

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(sign in visitor center)

As the ash from that explosion solidified under its own heat and weight it created a rock type known as “tuff”. While that determines its composition, the park’s tuff owes its shape to a very different eruption that started 600,000 years ago – the Newberry caldera fifty miles to the south. It spewed out enough basalt to cover an area the size of Rhode Island. This basalt reaches all the the to the southern margin of Smith Rock State Park, and since basalt is tougher than tuff (ha!) it trapped the Crooked River, forcing it to erode in one place instead of shifting around as rivers prefer. This constrained erosion created the steep pinnacles that make rock climbers starry-eyed.

The photos below show the two sides of the river – steep basalt cliffs on the left, softer tuff on the right.

 

Someday I’ll get out here with my climbing gear, this summer just wasn’t the chance. Heather and I instead hiked the Misery Ridge trail along the river and up steep switchbacks over the spine of the park. Following very good advice from my friend Kate we decided to do the loop clockwise in order to ascend by the less steep trail and descend on the stairs.

smith rock hike map

map from AllTrails.com – we did the loop clockwise

The park is littered with strange hollow rocks, like little fairytale huts for the four-legged park residents. Some are large enough to fit humans!

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Heather enjoying the shade

These fantastic shapes were formed by pressurized bubbles in molten but rapidly cooling tuff, and have slowly eroded out of the cliffs. There was a whole village of them near the junction of the River and Misery Ridge Trail.

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Looking up at Monkey Face from the River trail. Heather christened my head wear “the typical dorky geologist hat”. I have no shame.

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Heather couldn’t resist climbing some more rocks before descending the stairs

Temperatures were predicted to get up to 97 degrees that day so we started at 8:30 AM. After a leisurely stroll along the river and a significantly less leisurely struggle up the ridge we reached the top at 11 AM for a celebratory round of gummy candy overlooking the famous Monkey Face formation.

Scores of people were ascending the stairs at noon as we were passing them going downhill. Several people were prostrate on the side of the trail trying to cool down, and most were markedly miserable.  Smith Rock is a popular park on good roads close to civilization (Bend) and the trail is only 4 miles. This might lure visitors into a sense of complacency but it’s not by any means an easy hike. The signs at the trail heads recommended sturdy boots and drinking a liter of water every two hours while hiking – evidently it’s not exaggeration. I guess the trail is called Misery Ridge for a reason.

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I may never climb the 5.14 (insanely difficult) route up Monkey Face, but at least I climbed its mini-me on the playground!

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After eating lunch and saying goodbye to Smith rock we stopped by an auto shop to address Jo the Adventure Civic’s warning light (she’s never a fan of the climb over the Cascade passes), and then made our way to the beautiful Elk Lake USFS campsite 45 minutes southwest of Bend. We had a much longer hike planned for the next day, so we settled in for some serious relaxation at the lake shore…

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Life is tough 😛

Sources:

Heather’s wonderful photos!

 

 

 

 

One thought on “Smith Rock Hike: Volcanic rocks, volcanic heat

  1. Pingback: Sisters visit South Sister (and Green Lakes) | Blue Marble Earth

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