The AnglerDeep Stream was deep. It was the first of the Rangitata's channels, I knew there were another five kilometres of channel crossings in front and that I'd better get used to it, but this one looked too difficult and I followed it down.

Back at Mt Potts, Mark Dewsbery had drawn with his finger in the dust. Go past the superbin, cross the airfield, follow Deep Stream and just before Potts River you'll see a cairn and 4WD tracks. That's where you cross.

An angler held up to me, with two fingers hooked into its gills, a dangling silver trout. Water upwelled under my boots - seepage from the Potts River probably. There was no 4WD track, no cairn but I should cross Deep Stream before it was further swollen by the Potts River so I broke out the Lekis, adjusted them to height, undid the waist buckle on my pack and waded in. The bottom was slippery with brown algae. The water was very cold. and the water deepened until it was halfway up my thighs and rising. For the first time in a South Island river, I heard the second voice - maybe, maybe we should go back here, find that cairn. I didn't, I kept on, it got no deeper and I hauled out the other side, my legs bright red with the cold.

I stood tightening my cap against the wind. I was out on the stony plain of the river now and I looked at the hummock that rose there. The ancient city of Edoras once crowded the shoulders of this small waterbound mountain, a walled city of Men, protected by the river's channels and steep flanks of land that rose 100 metres to its summit.

EdorasNothing now remained - DoC had insisted that every block of polystyrene, every vehicle track should go. Wingnut Films dutifully restored the island, otherwise known as Mt Sunday, but you could see why they'd chosen it for a Lord of the Rings shoot. From this angle the high peaks, the perpetual snows, and the huge tumbled ice fields of the Garden of Eden Ice Plateau rose up behind, and the place was a vision. Erewhon, then Edoras - the Rangitata River Valley was a place where the imagination kept unreeling. Mine too. I'd dreamed about this river. Dreamed at Pinnacle Hut of bodies bumping against my legs. How safe was it as a tramping route?

When doing the trail report, I'd discussed all this with Mesopotamia's Sue Prouting. The consensus seemed to be - the crosspoint down-river of Mt Sunday and upriver of the Potts River junction was safe in summer - unless, that is, it wasn't.

Dust wraiths swept towards me, veered and vanished, then rose again. The river bed was as dry and stony as the Gobi, so windblown by the gathering norwester that thistle seeds came flying towards me with the wavering speed of tracer bullets.

One by one I came up to the channels. What looked like just another line of stones would begin to ripple. One after another - I stopped counting after 30, but most were shallow splash-through sheets and none had the depth and speed of Deep Stream - until the last, which looked dangerous.

Rangitata RiverBeyond this 15-metres of swift glass was the line of willows Sue Prouting had described as the best entrypoint onto Mesopotamia. But first, cross your river - swift and deep with a scooped wave and a little frill above every submerged boulder. But braided rivers are good like that. I hiked upstream and came to a place where the channel shoaled and broke into two, then three.

I walked onto Mesopotamia along a 4WD track through yellow grassland, but the homestead was still an hour away.

Dr Sinclair's grave

My map showed a red star - Dr Sinclair's Grave. I parted the briar rose and peered at the concrete overcoat of a former colonial secretary, drowned in the river on March 26, 1861. I gazed at the poignant stones here of two young Prouting brothers. In 1972, Allan dead by car crash at age 18. In 1980, Peter dead by plane crash on the station's upper terraces at age 23. The rhymed poetry on the stones might have been sentimental outside this place - here it seemed like simple fact. These were mountain boys, laid to rest under starry skies in the land they loved.

"Get your feet wet?" Malcolm Prouting leaned out of his ute as I came up by the barn. He radioed through to his wife to say I'd arrived, and I went on up to a farm cottage.

That night I went up to see Malcolm. How much of a problem was the river to hikers?

"It's hard to predict it, but Speed could probably put the punters right on the day. It can come up quickly. Today - fine. Tomorrow? The northwester is here now and by tomorrow evening it'll be on the way up. Other times it can be bank to bank and dirty. It's boiling and brown and you watch trees go past like cars."

What were the chances of putting Mesopotamia on Te Araroa's route? Malcolm didn't seem wildly keen, but he acquiesced. I'd walked through on the DoC fishing access route, and that joined to a public road. Trampers could stay at the same cottage I'd booked into.

We stepped into a room and onto linoleum that'd been beautifully inlaid with a merino head. This was the animal around which the station revolved - the fleecies, the shearers, the shepherds, the head shepherds, the managers, the owners depended on it. The Proutings had been on Mesopotamia since 1943 but the room was stocked with photos and books that honoured a 142-year rollcall.

Butler was a little insecure within it. He'd bought the separate runs that became Mesopotamia in 1860, built up a herd of 3,000 sheep, sold up in 1863, and returned to England soon after. The Butler painting that hung on the wall here illustrated the problem. If you squinted, the background could be New Zealand, but the buildings were chalets. And that was Erewhon's problem. The woolsheds were there, also certain natives seen as pliable, the Rangitata and the Alps. Butler's considerable intellect inhabits this landscape though only to snipe at the various follies of Europe.

"Everyone goes on about Butler but most of the locals think he was an idiot," said Prouting. "He put his thatch on the wrong way on the roof."

"Erewhon," I said. "It's a famous book."

"Yeh. We have a copy here. A number of our people have tried to read it. They get to the first chapter and wonder what the hell it's about. We're people of the land really and not all that bullshit."

I arranged to meet Malcolm at the barn in the morning. I wanted to go round the station with him if the rain continued but if it dawned fine, I'd set out again.

I went to sleep to the sound of rain, but woke later to a tangled chorus that went on and on and on, and seemed strangely comforting. The dogs of Mesopotamia were howling at the moon.

Malcolm Prouting and workmatesNext morning I went down to the barn.

"The weather looks good," said Malcolm. "If I were you I'd be bolting."