Aconcagua, West Buttress. In early January Dr. Gene Mason, Ralph Mackey and Dr. Richard Hill made a new route on the west buttress of Aconcagua (22,835 feet). The ascent took them seven days from the Plaza de Mulas. The route led up two chutes. They established a high camp at 17,000 feet below the upper chute. The latter was ice-filled but gave access by a broad ledge to the northern side of the peak at 19,000 feet.