South Sister
Started: 2017-07-19 20:54:00
Submitted: 2017-07-19 23:43:49
Visibility: World-readable
11 July 2017: In which the intrepid narrator climbs another cascade volcano
My mother rented a vacation house in Sunriver, Oregon, for a week in July and announced that we were all expected to attend. I took a look at the map and realized that this part of central Oregon was nestled up on the eastern slope of the Cascades and was teeming with volcanos. (I ended up calling this "Cascade volcano week" since we visited a different volcano every day.) Many summits were technical climbs on crumbling volcanic rock, but the tallest local peak, South Sister, the tallest of the Three Sisters, had a summer trail all the way to the summit. At the very least it ought to be easier than Mount Hood.
My brother Willy and I set out to climb South Sister on Tuesday morning, 11 July. We drove past Mount Bachelor (standing apart from the Three Sisters) to the Devils Lake Trailhead. (Still infected with Hamilmania, I decided the Three Sisters must be Angelica, Eliza, and Peggy.) We hit the trail at 08:00 and began climbing through a wooded valley along an intermittent stream. After an hour of hiking we hit treeline at about 6500 feet and immediately found ourselves walking on packed snow. We briefly lost the trail at a four-way junction, then found it with the help of a pair of skiers who were hiking up the mountain, presumably so they could ski back down again. (It was not immediately clear to me, though, where the best skiing was on the mountain; while there was a great deal of snow on the south-facing slope we climbed, it wasn't in a single continuous line.)
The trail led north, across a broad flat plain mostly covered in snow, where we got our first good view of our route.
On the far side of the plain the mountain -- and the climb -- began in earnest. I tried to follow the trail with mixed results; in the middle of July the trail was only intermittently visible under the snow, requiring some creative route-finding. The snow was stable and , but I had neglected to bring any of my snow-climbing gear, not even my trekking poles. Willy did bring his crampons and ice axe, and used his crampons to ascend one pitch of snow beginning to melt in the morning sun, but he gave up on the crampons when the snow pulled them off his feet, and he joined me on the rib of rock that I'd found.
Most of the foot traffic seemed to doing an ascending traverse on a large snowfield, but we were not especially interested in following the snowfield and looked instead for a route ascending dry ground -- with the bonus that this appeared to be where the trail was actually supposed to go. We made our way up a narrow patch of dry ground between two large snow patches toward a vent sticking prominently out of the side of the mountain below Point 9017. Most of the south side of the mountain was small dark gray rocks with the general consistency of a cinder cone, but the vent was formed by lighter more fluid rock that formed large blocks and was easier to climb on. (The vent clearly had a local maxima in person, but with only twenty or thirty feet of prominence above the mountain, it didn't earn a closed contour on the USUS 7.5' topo; it's visible only as a line at 8560 feet.)
Above the vent we found the obvious trail ascending to the saddle connecting Point 9017 to South Sister, climbing through larger boulders (mostly the size of a small fridge) which generally stayed put when I stepped on them. This particular slope reminded me of many of the talus-strewn slopes I've climbed in Colorado -- in particular the south slope of Chiefs Head Peak.
We stopped for a snack on the saddle with a great view of Lewis Glacier and the small tarn below it, dominating our view of South Sister. To the south and west we could see snow-covered volcanos dotting the horizon.
To our south-west, on the slope of the mountain below us, we saw a weird circular pattern of rock and snow at least a mile in diameter. From our vantage point it looked like a labyrinth; or maybe a map in an epic fantasy where the citadel is located precisely in the middle of the map, surrounded by rolling hills, without regard to geologic forces, because the plot requires it. My map gave the name as Rock Mesa, and semi-helpfully annotated the ground as "lava". I eventually concluded it must be a vent of brittle shield lava, likely a'a, that flowed from the middle on a relatively flat surface and pooled in concentric rings.
We continued our climb on the ridge separating the Lewis Glacier to our right from the rather more anemic Clark Glacier to our left. This was a single unbroken slog up a thousand vertical feet on rather stable talus. Most of the slope was covered in red lava rocks that looked like it ought to belong in an ugly garden as landscaping rock. I had never seen these rocks in the wild before, but I suppose it must exist somewhere so that it could be mined and put in little plastic bags and sent to Home Depot.
After an interminable slog we reached the summit crater a little after 13:30, after five-and-a-half hours of climbing. The crater ring was a tiny ring of rock surrounding a large snowfield. From where I stood it wasn't immediately apparent where the highest point on the summit was, so I decided to circumambulate the crater in a clockwise direction (that of course being the most auspicious direction in which to circumambulate). I got a quarter of the way around the crater when the crater gave out, so I set out across the snow field to find the actual summit on the eastern edge of the crater.
We ate lunch on the summit and gazed out at the volcanos stretching out in a relatively straight line to the north -- the next two sisters were immediately north of the summit, and we could see Mount Jefferson, Mount Hood, Mount Adams, and Mount St Helens in the distance.
We retraced our steps back down the mountain to descend. On our descent we had the major advantage of gravity working in our favor, and for the most part the slope was gentle enough that we didn't have to worry (much) about sliding too far down the mountain with each step. We descended the top thousand feet quickly, then picked our way down past the vent and around the snow fields that obscured the trail.
At first I optimized my route to spend most of our time on rock, rather than on snow, but when the snow grew gentle enough (and the rock grew sparse enough) I decided to give the snow another chance and we descended back down to the plain with minimal further difficulty. We bid South Sister farewell as we descended on the trail below timberline, eventually arriving at the trailhead at 17:00. We'd spent nine hours on the mountain, climbing almost five thousand vertical feet to ascend the third-highest point in Oregon.
The only major casualty of the climb was a sunburn on my legs. After getting sunburned on Mount Hood last month, I spent most of the day applying and reapplying sunscreen on the rest of my body, but I forgot about my legs when I converted my pants into shorts. This was a small price to pay, though, for my opportunity to climb another great mountain.
