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South Sister

Oregon's Third-highest Peak

“Charity”

Stratovolcano in Willamette NF, Three Sisters Wilderness, Cascade Range near Sisters, OR

Her summit reflected in the waters of the Cascade Lakes, South Sister (10,358’) looms over the forests of Central Oregon in silent grandeur. In winter, the peak is blanketed in white, but the summer sun melts much of it away to reveal a multicolored mountain dotted with snowfields and glaciers. Views from the summit stretch over much of the Cascades, into Washington to the north and California to the south.

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South Sister is a stratovolcano that has been erupting off-and-on for the last 50,000 years, though long gaps in activity have been noted. Flows of rhyolite, dacite, and basaltic andesite comprise the bulk of the edifice today, layering the mountain in hues of red, purple, and gray. The mountain is far from finished: a lava flow on its southern flank is one of the youngest in Oregon, and an area of uplift in the early 2000s indicated a magma chamber filling beneath the mountain.

The summit is attainable, but it’s not easy. A climbers trail leads up the southern slope and requires no technical gear or training but is most certainly taxing. Most hikers bound for the summit begin at Devils Lake. Round trip, the hike is 12.5 miles with roughly 5,000 feet of elevation gain to the peak. It is a long and steep hike with quite a payoff: on a clear day, the view from the top reaches from Rainier to Shasta.