Mount Patterson, East Buttress. From Bow Summit, Peyto Lake and Mount Patterson are a colorful view. John Rupley and I looked at the peak to find a suitable and safe route through the confusion of cliffs, glaciers, and summit bands of questionable rock that face the Icefields Highway. A sharp rock and ice ridge appeared to cleave these features, apparently holding the key to a classic alpine route on this major peak, which apparently had previously been climbed only by snow and scree on the reverse side. The first problem was fording almost to the hips early in the morning; then a forest, followed by two or three hours of alternate cliff scrambling and a long snow couloir. This put us on a glacierlet that fringes the east and north faces of the mountain. Ahead of us was a prow of evil-looking rock that buttressed the summit; above the prow, a sharp ridge careened on, blossoming with threatening cornices. The prow was a problem, being considerably more difficult and longer than it had appeared, some fourteen rather than the nine anticipated leads. A few pitons gave moral support on the first two leads. Rock was alternately good, bad, and to our surprise sometimes of a magnificent Dolomite stability and form. Once a nose of pure rubble turned us back, and we had to traverse hundreds of feet out of our way to find a new entrance to the upper buttress via an exposed flanking wall that took us to a spectacular ice crest. For a half-hour we waited, watching a display of lightning, with buzzing hair and ropes, some distance from the climbing irons, axes and pitons. By now we were too high to retreat, and fortunately the skies cleared some. We kicked and cut steps over the major cornice hummocks, and in-between climbed two “book-edge” steps of excellent rock on the airy crest. Finally came an exposed and very unstable cornice, where we sank hip-deep, and an exposed traverse to the left where I could find a breach in the summit cornice. The climb is exceedingly alpine, involving the use of many climbing techniques in addition to a constant route-selection problem. We found an easy though tedious descent on the west slope, turned the mountain on the south and reached the highway just at dark.