Three Tarn Pass Route

The Three Tarn Pass Route is a 14.4 km (8.95 mi) one-way crossing from Ada Pass Hut to Bobs Hut, over the lower true-right branch of the Maruia and down the West Matakitaki valley. Allow 10–14 hours for the crossing; many parties camp and split it over two days. That distance starts at Ada Pass Hut and excludes the 10 km, roughly five-hour walk in from Lewis Pass on the St James Walkway. This is remote, mostly unmarked backcountry travel for experienced trampers with strong navigation and river-crossing judgment.

From Ada Pass Hut, retrace about five minutes to the Maruia footbridge, then climb the true-right branch. Tape markers through the trees can be difficult to follow; the route rises steeply through a dry creek bed, scrub and tussock before reaching open alpine ground, an unnamed tarn and the narrow pass. Some maps show a different, higher pass on the true-left branch. This route uses the lower true-right crossing.

A steep chute and loose scree descend from the pass to three small tarns beneath a jagged ridge. The basin sits in a glacially carved valley. From there, expect rough tussock, boulders, boggy ground and repeated stream crossings. At the moraine wall, the route leaves the river and climbs above a small gorge on the true-left side before returning to easier river flats. The last five kilometres follow an unmaintained river-valley route to Bobs Hut; a crossing near the hut can become difficult after heavy rain.

Ada Pass Hut is a serviced 14-bunk hut and must be booked; the St James Walkway approach from Lewis Pass is an extra half-day. Bobs Hut has eight bunks and is first come, first served. The pass can retain snow and ice into summer, so late summer is usually the more practical season, after most snow has melted. Dogs are not allowed on the St James Walkway or in the national park. Check current snow, river and access conditions before setting out.