On July 29, Tony McLane and I flew in to the Plummer Hut in the Waddington Range, and that afternoon we dropped to the Tiedemann Glacier and a bivy at Sunny Knob. The next morning, we negotiated the glacier below the southwest face of Asperity Mountain and mixed climbed past a bergschrund to gain a vague buttress near the center of the face. We climbed this for eight long pitches on generally excellent rock, culminating in a 60m offwidth in a corner that reared to slightly beyond vertical. This gained a lower-angled middle section, where we made fast progress up snow couloirs and low-5th-class rock. Eventually the face steepened again and we followed a ramp leftward to the Northwest Ridge route. A short bit of climbing in a beautiful position brought us to the summit. Southwest Face (950m, ED1 5.10+).
The descent from Asperity to the Tiedemann has a nasty reputation that we found well deserved. We descended the east face toward the col with Serra 5, first with slightly stressful downclimbing and then with some diagonal rappels around a serac once the ice slope became firm enough to make V-threads. We bivied at the col and the next morning set off down the couloir that drops toward the Tiedemann. We soon exited the couloir onto a chossy rib, where at least the majority of the rockfall was self-induced. A long rappel over a bergshrund brought us to a tedious traverse to the top of Carl’s Couloir. This proved relatively straightforward, although we still required a rope-stretching rappel over the bergschrund at the bottom. We then downclimbed exposed glacial ice to the Tiedemann Glacier and slogged back up to the comforts of the hut.