Thompson Pass Route

Thompson Pass Route is a 5.4 km (3.36-mile) one-way crossing from the Waiau Valley track junction, via Lake Thompson, to the D’Urville forks. The crossing itself is estimated at about 4½ hours; the separate walks into and out of either valley add substantially more. This is an unmarked alpine route, not a standalone day hike. It suits only experienced parties comfortable with off-track travel, steep ground and river crossings.

The eastern leg starts with river crossings and a scramble out of the stream, then climbs a steep gut or nearby ridge toward Lake Thompson. The lake lies in a high rocky basin at about 1,700 m. From there, a short climb over a grassy tongue and rock reaches the 1,796 m pass. The pass is easier to identify from the Waiau side than from the D’Urville Valley, so this is the clearer direction to approach it.

The western leg drops nearly 700 m over scree and steep slopes to the D’Urville forks. One route description follows cairns and keeps to the true left to avoid ravines; other parties have used a southeast bypass after reporting fatal accidents on the direct descent. The exact line is disputed. Treat the mapped route as a corridor rather than a safe, marked path, and use current local advice and expert navigation before committing to the descent.

Lake Thompson’s turquoise water sits beneath a stark bowl of broken rock, tussock and steep ridges. From the pass, views open back toward the lake and the heads of both valleys. A V-shaped notch toward Waiau Pass makes a distinctive frame from the lake basin. Alpine herbs and woolly edelweiss have been reported among the rocks near the pass, though flowers are seasonal.

There is no car park at either end; both are remote backcountry junctions reached by longer routes. Informal tent sites have been reported by the lake, but it is not a serviced campsite. Snow can fall at any time of year, and avalanche terrain lies in the wider alpine area. Dogs are not permitted in Nelson Lakes National Park.