Half Dome, Northwest Buttress. In September 1969, Bob Jensen and I climbed the northwest buttress of Half Dome. The route starts several hundred feet north of the regular northwest-face route at the left edge of an arch about 450 feet high. Mixed climbing leads up the arch, following detached slabs and recesses past several ledges for three pitches. From a position about 50 feet under the top of the arch, on a group of small ledges, hard nailing leads up and to the right, following the juncture of the arch and the smooth face beside it. Reaching a tiny ledge, one completes the pitch by following a horizontal row of bolts (some hangers removed) 70 feet to the right. From there, one can pendulum to a crack system, regain lost altitude, and pendulum again to get out from behind a long expanding flake. A ledge 140 feet above the end of the bolts offers a good bivouac site, after nailing first in a dihedral, then up a poor thin crack. On the next pitch, ending in a wide down-sloping ledge 150 feet up, occasional aid pins were used to ascend a deep dihedral, then pass a triangular roof on the right. The short final free pitch traverses left and then up, avoiding the summit overhangs. NCCS IV, F7, A3.