This is a challenging tramping route requiring tramping and alpine experience, and is not recommended in winter due to avalanche danger.
From the car park, the marked track meanders up the valley through spectacular alpine vegetation. From the head of the valley the route leads up towards the saddle; from this point there are no permanent track markers. Cross the Gertrude Stream below a large, steep waterfall area, about halfway up to Black Lake.
From here, parts of the track are very steep and not suitable for those with limited tramping experience, or a dislike for heights. The track goes up steep rock slabs and is treacherous when wet or frosty - there are steel cables to assist you.
From the head of the valley continue up through the boulders to the saddle. Return the same way.
Breathtaking views of the valley and part of Milford Sound/Piopiotahi can be seen from the Gertrude Saddle. This track provides excellent access to the mountains for experienced climbers.
This track is reached from the Gerturde Valley carpark, about 98 km along the Milford Road from Te Anau.
Know before you go
After rain there are some creek crossings so expect to get wet feet.
There are no permanent markers above the bushline, so alpine and navigation skills are essential. Rock cairns placed by trampers mark the route, but be sure to follow your own judgement and use a topographical map.
This is an alpine route and is subject to avalanches after snow. Check with the Fiordland National Park Visitor Centre for track conditions before starting, whatever the season.
For more detailed track information see 'Moirs Guide South' edited by Robin McNeill. Available from the Fiordland National Park Visitor Centre or Alpine Club website.