Istor-o-Nal was first climbed on June 8, 1955 by the Americans Joseph E. Murphy, Jr., and Thomas A. Mutch, led by Pakistani Major Ken Bankwala, on a Princeton Mountaineering Club expedition. They climbed the west ridge, starting from the south side of the peak on the Tirich Glacier. Their small, minimally financed expedition (by the standards of the time for high-altitude mountaineering) achieved what was then the second highest summit attained by Americans.