A Brief Guide to Lake Mavis

Nestled in an alpine basin near the main divide in Arthur’s Pass National Park, Lake Mavis has long been on my dream list. In March 2023 I set off on a solo trip to finally make it a reality.

Lake Mavis is most easily accessed via the Mingha-Deception Route. As such it can be approached from either the eastern or western side of the alps. I chose the eastern approach, which starts at Greyneys Shelter; located approximately 5 km east of Arthur’s Pass Village on State Highway 73.

The Bealey River must be forded within the first 10 minutes of the walk. It’s the first of many unbridged river crossings on this trip, so if it’s been raining (or is forecast to rain) then this hike is unlikely to be safely achievable.

After crossing the Bealey a marked track meanders up pleasant river flats on the true-left of the Mingha River. Eventually the Mingha needs to be crossed and soon after recrossed. At around the 90-minute mark, the track enters beech forest and a 100m ascent to Dudley Knob commences; fleeting views up and down the valley are soon on offer. The track then drops down again and the next hour or so is spent in the forest with the Mingha rushing nearby and several side streams to cross. The 2-bunk Mingha Bivouac is located in a small clearing and makes a great place to stop for lunch.

Soon after the bivvy the track passes the impressive Kennedy Falls (150m) and then ascends through sub-alpine scrub as it approaches Goat Pass (1070m). Near the pass the track runs across a series of boardwalks traversing sensitive wetlands. Just a stone’s throw from the pass lies Goat Pass Hut (20 bunks), which is where most people stay the night when doing the Mingha-Deception Route.

Clockwise from top-left: (1) Kennedy Falls (150m); (2) Mingha Valley; (3) My campsite; (4) Outlet of Lake Mavis;

The route to Lake Mavis commences just before reaching Goat Pass. For me it had taken just over 4 hours to this point (including lunch and all other breaks). The turn-off is marked with a cairn but can be difficult to spot. From here there is an occasional semblance of a path, but it is not formed or maintained and can be easy to lose. Navigation and route-finding skills are essential. In places the route is also very steep, there is scree underfoot, and some clambering required. With a heavy pack I found this section to be quite the slog!

After around 400m vertical (from the pass) the gradient thankfully begins to ease off. Here the 60m outlet waterfall of Lake Mavis becomes visible, but the lake itself remains hidden. It’s not until a couple of minutes out from the lake, around the 1,600m contour, that the spectacular and welcome sight of the destination comes into view.

I pitched my tent at the western end of the lake (there are several other suitable spots dotted around the lake shore). Total time for me from Greyneys Shelter worked out to be around 7 hours.

The next morning, following a beautiful starry night, I packed up and returned the way I came. The walk out, being mostly downhill and with less breaks, was a lot faster at just under 5 hours.

Below are some video highlights which visually explain the above in more detail … I hope you enjoy!

Video highlights from an overnighter to Lake Mavis