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Sunlit Summit

Twin Peaks

Elevation: 13,216 ft.

Prominence: 423 ft.

Isolation: 0.6 miles

Technical Difficulty: Class 3+

East Twin

West Twin

Twin Peaks Guidebook


The Twin Peaks are a pair of sharp rock horns at the head of both the Mammoth Glacier and upper Titcomb Basin. They are hidden from most points in lower Titcomb, but from Fremont Peak or other nearby 13ers, these symmetric spires stand out.

The East Twin (which has a summit register) has an elevation of 13,216 ft. according to LiDAR data (coords. 43.16007° N, 109.65883° W), while the highest LiDAR point on the West Twin comes in at 13,214 ft. (coords. 43.15848° N, 109.66157° W), a difference which is within the uncertainty of the analysis due to the West Twin’s exceedingly sharp summit block. Sight-leveling and GPS measurements have similarly failed to determine which summit is higher. Thus, it is established protocol amongst all finishers of the Wyoming 13er list that both summits of the Twins must be climbed to unambiguously claim the high point.

General Considerations

As mentioned above, until a definitive measurement can be obtained, you should touch the top of both the eastern and western summits in order to claim an ascent of the Twin Peaks, even though only one of these summits is actually a ranked Wyoming 13er.

The Twins can be climbed equally well from Titcomb Basin or the Mammoth Glacier. The climb from Titcomb is a bit steeper, though the Mammoth Glacier approach has crevasses and turns to ice in the late season, so the choice of route will depend on your experience and comfort level with steep snow and rock versus crevassed glaciers as well as your other objectives in the area.

Route 1: Northwest Slopes – Class 3+, Moderate Snow

Reach the upper Mammoth Glacier by any number of routes: the most obvious approach options include Split Mountain Pass, Glacier Pass, and via Scott Lake (see Desolation Peak description). Beware of serious crevasses on the glacier. From the flattish southern arm of Mammoth Glacier around 12,000 ft., climb moderate snow slopes up a glacier lobe that reaches nearly to the saddle between the East and West Twin. In the late summer, this lobe of the glacier melts down to solid ice, and the upper section may even harbor seasonal water ice depending on the year.

From the saddle, the East Twin can be reached by walking up talus, but the West Twin requires a bit of rock scrambling over steeper blocks near the summit.

Route 2: Southeast Couloir – Class 3+, Serious Snow

From upper Titcomb Basin, follow the usual off-trail route towards Knapsack Col, hiking over some mix of snow, scree, and grass depending on the season. Climb north up a steep scree embankment around 12,200 ft. to reach the hanging glacial remnant directly below the Twins’ southeast cirque. Alternatively, you can reach this route by crossing Knapsack Col from the Peak Lake region and traversing north into the same hanging cirque.

From the snowfield, head for the saddle between the Twins. The snowfield does not quite reach the saddle, and the final 200 ft. requires some steeper climbing up a narrow, left-angling couloir. This couloir offers a snow route in the early season, but it turns to a nasty mix of ice, scree, and dirty class 4+ cliff bands later in the summer. From the col between the Twins, the east summit is a short hike while the west summit requires a short scramble.

Twin Peaks Map

Click title to show track
Northwest Slopes Route
Southeast Couloir Route

Twin Peaks Panorama - East Twin

Twin Peaks Panorama - West Twin

Twin Peaks Photos

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