Along the Backbone of the Big Bend, Canadian Rockies. With the support of three air supply-drops at an estimated distance of four days’ hike apart, Sterling B. Hendricks, Donald Hubbard, and Alvi E. Peterson undertook to travel the alpine uplands from the mouth of Mica Creek, on the Big Bend Highway, B. C., to Flat Creek, on the Canadian Pacific Railroad. Beginning July 5 and proceeding directly up the wooded slope to Fred Laing Ridge, then continuing along the snowfields, rocky ridges, alplands, and flowering meadows, through Anemone Pass and over the east shoulder of Northeast Peak, the first supply-drop was located on the glacier directly on the route in mid-afternoon of the fourth day. After one day’s rest near the upland source of Bigmouth Creek, the party proceeded along the wooded slopes and back country west of Trident Peak to a camp below the Escarpment neve. The following day was devoted to a reconnaissance trip across the névé and to the top of Escarpment Peak, about 10,000 feet, a first ascent. Neither the Escarpment Face nor the rocky arête of Escarpment Peak offered a wholesome route to the south. Along the acceptable route south over Rhea Pass and along Mist Glacier and in the view from Escarpment Peak, we saw how repulsive were approaches to Mount Neptune. On July 13, the party reached the second drop-area to the south of Mount Neptune, only to find that a broken ice cornice from the ridge above had started an avalanche that obliterated all traces of supplies. We considered surviving for ten days on the bulbs of yellow adder’s tongues or fawn lilies as an emergency diet until we might traverse the unknown country and reach the third supply drop on the Belvedere névé near Mount Sir Sanford. Trident Creek was finally chosen as an escape hatch. After returning to the shadow of Mount Neptune, crossing Mist Glacier to Dolphin Pass, down and across Trident Glacier to Trident Creek Valley, which drops over a mile in less than three miles with extensive areas of devil’s club and slide alders, the party arrived at the end of two days on the west shore of Kinbasket Lake, supplementing the last meal of rice with mushrooms and the last of the sugar with berries. The next day, July 16, while hastily assembling a raft, the party was retrieved, fed, and returned to civilization by two pole-cutters.