The gates of Mt Aspiring Station remind me of the generosity of four generations of the Aspinall family who've allowed trampers and climbers access to the valley since the 1920s.
The last 10km is a fine-weather road only. The water level is low today and it's no problem driving through several fords.
Warning: don't attempt the fords when the water is high. Innumerable unwise drivers have been forced to abandon ship.
The road ends 54km from Wanaka at the Raspberry Creek car park, administered by the Department of Conservation.
A couple of tourists approach. "So beautiful here, but ze road, she is diabolical."
I explain there's a regular shuttle service from Wanaka for those unfamiliar with unsealed roads.
First-time visitors should attempt the Rob Roy Glacier walk. It's about 10km and three hours return for the moderately fit. Beginning 15 minutes from the car park at the swing bridge crossing the West Matukituki River, the track climbs up through beautiful beech forest. We're enveloped by dark green silence.
The peace is shattered by a family of four noisily slipping and sliding downhill.
"It's far too hard for us," puffs Mum. They're all wearing Jandals.
Alistair rolls his eyes.
The Rob Roy Glacier walk is a good option for first-time visitors to the valley. Photo / Supplied
We scramble up and over a couple of rocky slips, but otherwise it's a relatively easy climb.
The track emerges into an open rocky area of low alpine vegetation, dominated by the spectacular glittering blue-white ice of the Rob Roy Glacier opposite.
Intermittent grumbling from the glacier and the rasping kee-ah call of the world's only alpine parrot echo off the surrounding rocky cliffs.
An Australian couple are sitting on a rock eating their lunch.
"That glacier's surreal," he says.
"Mate, we may have the wildlife, but you Kiwis have the most magnificent scenery by a long shot."
Those averse to climbing could opt for the longer four-hour, 18km return route up the river valley to the Mt Aspiring hut. Apart from a couple of steep bluffs, it's an easy pleasant walk through grassy tussock land. Beech forest edges the valley, which culminates in rugged snow-capped mountains.
You're likely to be closely inspected by a mob of curious heifers. City dwellers may find their company intimidating, but they're harmless.
A small two-room, iron-clad hut sits to the side of the valley in front of the beech forest. The basic Cascade Hut was built by members of the Otago Branch of the NZ Alpine Club over four days in 1932. Building materials were brought in by packhorse.
Twenty minutes beyond is impressive, schist-clad, 38-bunk Aspiring Hut, completed in 1949. James K. Baxter wrote Poem in the Matukituki Valley here.
These days, it's used mostly by trampers. Climbers often save time by taking a helicopter from Wanaka to the Colin Todd Hut at the foot of Aspiring's north-west ridge.
Maori called Mt Aspiring, the only 3000m peak outside Aoraki/Mt Cook National Park, Tititea (steep peak of glistening white). It's also known as the Matterhorn of New Zealand.
Like most high country areas, weather in the valley can change in minutes. Even in summer be prepared for howling winds, rain and freezing temperatures.
Don't walk? Then sit on a rock and enjoy the view. A visit to this unique, unspoiled piece of spectacular back country, only an hour's drive from Wanaka, should be near the top of every bucket list.
