Mount Earnslaw is a large massif consisting of micaschist and comprising two main summits, East Peak (9,308 ft) and West Peak (9,261 ft), together with a number of lesser peaks, separating the Rees Valley on the east from the Dart Valley on the west, at the head of Lake Wakatipu. The massif approximates in plan view to a letter “H” with the main summits lying at the ends of the cross arm and two deep valleys incised from the north (Bedford Stream) and from the south (Earnslaw Burn). A large hanging ice field occupies the south face overlooking the Earnslaw Burn, and a smaller one, the Birley Glacier, lies on the east flank. The north face is almost entirely ice free. Adjoining peaks include Turret Head to the south-west, Black Peak to the south-east, Pluto Peak to the north-west, and Leary Peak to the north-east (or more properly O'Leary Peak). The latter is separated from East Peak by Wright's Col, and Pluto Peak from West Peak by a deep saddle at the head of Bedford Stream.
The name, meaning “Eagles Hill”, was given by the surveyor J. T. Thomson, whose father came from the village of Earnslaw in Berwickshire. The first major attempt at ascent was by the Rev. W. S. Green in March 1882, but the summit of East Peak was not reached until 16 March 1890 by H. Birley, who was accompanied for part of the way by F. Muir. West Peak was first ascended in February 1914 by H. F. Wright and J. Robertson, who climbed it via Wrights Col between East Peak and Leary Peak, thence by the bare rock north face. East Peak has been climbed many times since, but West Peak less frequently. The most favoured route is from the Rees via Earnslaw Hut (3,500 ft), Kea Basin, and Wrights Col. The very small Esquilant Hut in Wrights Col affords shelter to a limited number of mountaineers and permits access to Mount Earnslaw and surrounding peaks. Several expeditions and climbs have been made via Bedford Stream, a tributary of the Dart River, and via the Earnslaw Burn. A privately owned musterers' hut in the Earnslaw Burn may be used with the approval of the owners and gives access to the southern parts of the massif. The twin peaks of Earnslaw are intermediate in height between those of Mount Tutoko (9,042 ft) and Mount Aspiring (9,957 ft), but they overtop all other peaks in this part of the South Island and so afford a vantage point for magnificent views of alpine scenery.
by Bryce Leslie Wood, M.SC., New Zealand Geological Survey, Dunedin.