Serpentine Traverse via North Branch

This is a challenging route with large sections that are untracked. The ridgeline is exposed and there are sections of challenging scrambling. It should only be attempted in good weather!

Starting on the Routeburn Track, follow the well-formed trail all the way to Lake Harris, enjoying the easy running while you can! Toilets and water are available at Routeburn Flats and Routeburn Falls huts, and there are also a multitude of streams along the way.

Just before Harris Saddle, take the obvious track to the head of the lake and follow this through to the Valley of the Trolls. From here, the trail grows less distinct and route-finding skills are required to find your way up above Lake Wilson. Keep right from the head of the valley and follow the eastern stream draining Mt Xenicus to reach the head of the stream, at 1480m. The route then continues to the flat top of a spur at 1520m, where there are views of the Lake Wilson basin.

From the lake, head north, dropping to a sidle beneath Mt Erebus on chunky scree towards the ridge. From the ridgetop, the Serpentine Range can be seen ahead, winding between Fiordland and Mt Aspiring national parks. Head through tussock, rock, alpine plants and small tarns along the ridgetop, avoiding small bluffs and sidling east (under Pt1715 on the topo map) to avoid a steep section of down climbing.

There is also a sheltered tarn, just below Pt1550, and from this dip in the ridge, head west to climb the spur ahead, which looks more challenging than it actually is. At the top of the hill at Pt1550 you'll be able to see all the way to North Col. This is a crucial part of the route - stay on the west side of the unmarked hump between points 1550 and 1555 to avoid a very steep section. From there, scope out a route over the rocks and look for good handholds before dropping down to North Col.

From North Col you will drop down the valley towards the Routeburn North Branch track. There is a rough route down the first part and then you'll have a challenging section of rock hopping through huge boulder gardens and bashing through dense scrub. There are lots of cairns but any track they once marked is largely overgrown. In warm weather, it might be quicker to simply follow the river. This section is very slow travel.

Eventually the valley opens out to large flats and you'll pick up the clearly marked Routeburn North Branch track on the true right of the river. From here, it's a relatively simple run back to Routeburn Flats Hut and then a very easy 8km on the great walk track, back to Routeburn Shelter.