The Gertrude Valley track gives access to Gertrude Saddle and excellent views of Milford Sound and the surrounding mountains. From the saddle, routes continue to Traverse Pass and Adelaide Saddle. Crags around Black Lake offer single and multi-pitch slab climbing of varying quality. Sickle Crag is the pick of the bunch with adventurous routes (grades 18 to 22). The Bog Farmer and Morning After slabs have excellent north-facing routes (grades 15 to 18). Other lines have been done on the south-facing slabs and walls between the lake and Gertrude Saddle but these tend to be mossy.
The track starts from the shingle pit just east of Homer Hut, crosses a wooden bridge and follows a washed-out road beside the stream. Cross the stream just before the last piece of forest and follow the track through bush and sub alpine scrub to the open valley. At the head of the valley is the large cirque of the Barrier Face with the stream from Black Lake descending on the true right. Follow the track on the south side of the stream, crossing it after 200m to scree slopes and slabs leading to Black Lake. While it’s a bit of a walk to the lake (one and a half hours), it is hard to imagine a nicer place for crag climbing, with swimming an option on warm days. To reach Gertrude Saddle (1410m) follow the steel cables to the terrace above the lake and below Barrier Knob, and traverse across and up to the saddle.