Dawn is hours away on a cool Fiordland night but the packed bunk rooms of Clinton Hut are seething with activity. Tramping boots stomp against wooden floors, bunks creek as their inhabitants fling their bodies around, and an urgent, sleep-fogged crescendo of angry whispers is building in the gloom.

“Shhhhhh,” hisses someone from a top bunk, directing their wrath towards the noisy hiking party who like to tramp in the dark, the New Zealand bush enveloping them in a silent black cloak.

“Shhhhh!” hisses another low voice, from the other side of the hut. “It is against the rules to be so noisy!”

The day before 40 strangers had set off from the tourist hub of Te Anau, full of energy and wearing fresh socks. Final flat whites were sculled at overpriced cafes and out-of-office signatures attached to emails.

In a soft, grey drizzle typical of this remote corner of New Zealand, trampers of varying abilities heaved 20kg packs on to a speedboat proclaiming “Adventure starts here” for the 40-minute journey across Lake Te Anau to the start of the world-famous Milford Track, in Fiordland national park.

Milford has become synonymous with beauty, a 54km, four-day tramp through beech forest, over glacier-fed rivers and up the climatic MacKinnon Pass, an alpine crossing more than 1,100 metres above sea-level.

One 100 years ago the Spectator magazine declared Milford “the finest walk in the world” – and the name has stuck.

There are nine “great” walks in New Zealand, with Milford the jewel in the crown. But as its popularity has surged so too have fears from New Zealand trampers and conservationists that the pristine natural environment is being spoilt by the hordes of tourists drawn to its beauty and supposed tranquility.

Facebook Twitter Pinterest The Mackinnon memorial at the Mackinnon Pass. Photograph: Murdo Macleod/The Guardian

Last year, nearly 120,000 people hiked the great walks; a 12.4% increase on the season before and nearly 50,000 more than a decade ago.

Nearly 8,000 walk Milford in the summer season, which is booked out again this year, and has raised hut fees from NZ$54 to NZ$70 a night. If you choose to tramp privately with Ultimate Hikes, you’ll be paying between NZ$2,000 and $3,500 for your wilderness experience, which includes booze, three-course meals and “total comfort in the last place you would expect it”, according to the website.

Contractors preparing the tracks over the winter season say they’ve barely finished clearing the native bush of human faeces and toilet paper in time for the next deluge of hiking boots about to descend.



Facebook Twitter Pinterest Prairie Lake on the The Milford Track. Photograph: Murdo Macleod/The Guardian

“On some of the great walk tracks, you find poos and toilet paper just littered down the side of the tracks,” a contractor told Radio New Zealand. “It’s disgusting.”

It is now harder to book a walk on the Milford Track than it is to see Justin Bieber or Adele live in concert in Auckland.

Ross Harraway, 74, has been a Department of Conservation hut warden on the Milford Track for nearly a decade. At close to seven feet tall, Harraway looks like Gandalf the wizard, and in the evenings moves silently through the beech trees with a staff, explaining the local flora and fauna to visitors.

“A lot of people aren’t interested in what is around them anymore, that’s what I’ve noticed,” says Harraway, talking to the Guardian from his cosy warden’s hut over a cup of billy tea.

Facebook Twitter Pinterest Kelly guides walkers as they climb towards Mackinnon Pass. Photograph: Murdo Macleod/The Guardian

“They are ticking off their bucket list and getting through it as quickly as possible. They have their headphones in, head down, get up on the pass [Mackinnon], take their photos and the tick is over. People do have a lot of different reasons for doing it ... but increasingly, people do it because it has become a bit of a status thing.”

Gerard Emery decided to tramp all of the great walks after seeing them advertised on an Air New Zealand flight. He tramps with old friends and they dine lushly every evening – steaks, tin mugs of whisky and creamy puddings for dessert.

Play Video 1:35 Walking the Milford Track: New Zealand's most popular trail

Like many trampers, Emery hits the great walks to enforce a digital detox in his life, but he’s been surprised by how few New Zealanders walk the famed tracks any more – and how crowded and tetchy the huts have become. These days, 67% of trampers on the great walks are foreigners.

“My latest adventure is to do the nine great walks, and this is number six of the nine,” says Emery outside Mintaro Hut, where he’s gone to escape the cacophony inside at dinner time.

“I am quite disappointed there aren’t more Kiwis on here ... there should be a hell of a lot more Kiwis walking on these tracks; we see very few.”

Facebook Twitter Pinterest After reaching the end of the walk, a boat takes walkers out of Milford Sound. Photograph: Murdo Macleod/The Guardian

John Kapeleris, an Australian, didn’t get interested in tramping till middle age. He is walking the Milford alone, a solitary, slightly aloof figure who strides ahead of the 40-strong group to try and be alone in nature, no easy feat when there are more than 90 people walking each section of the Milford each day, plus guides, hut wardens, maintenance workers and chopper pilots flying in supplies.

Kapeleris, who booked his Milford walk in 2015, tramps as a way to detox from his intensely urban life; the office-block job, suburban home and long daily commute in Brisbane, Australia.

“For me it is an appreciation of what there is in the world other than urban life ... it’s an escape. You can get away from the routine of work, the routine of commitment, the routine of obligation,” he says.

Last season, tickets for the Milford sold out within 90 minutes of being released. Mary, a vet nurse from Australia, tried for three consecutive years to secure a spot on the track. Last year – her fourth attempt – she set her alarm for midnight on the day tickets were released and was successful.

Facebook Twitter Pinterest Mount Elliot at the Mackinnon Pass. Photograph: Murdo Macleod/The Guardian

“Its become a highway, a conveyer belt,” says a Department of Conservation worker on the track, who didn’t want to be named.

“People come here looking for meaning, searching for some sort of solace. But the bush doesn’t just give that up. In the huts there’s so much squabbling and showing off. To me, Milford isn’t about tramping anymore, at least, not how Kiwis know it. ”

On day three, the 40-strong group rise in the dark after a disturbed night, in which a man who snored loudly was yelled at and booted down to the kitchen.

“It made me feel really self-conscious,” he tells the Guardian later. “I felt ganged up on.”

The climb up Mackinnon Pass is graded but challenging, and swaths of low cloud blow over the mountain, obscuring the view and bringing stinging spits of rain to frozen cheeks.

Along the way you pass signs designated as “Safe stopping areas” and “Bus stops”, and as your thighs begin to ache the beech trees thin and eventually disappear, giving way to mountain buttercups, alpine daisies and gentian.

The peak at the top of the pass – 1,154m – brings a brief and united merriment to the disparate and at times fractious group. Selfies are snapped, proud couples embrace and the paying hikers are presented with mugs of hot chocolate and biscuits from their guides.

Facebook Twitter Pinterest Boots hang outside Mintaro Hut. Photograph: Murdo Macleod/The Guardian

Soon the wind picks up and the temperature drops dramatically, prompting walkers to slog on to the Mackinnon Pass Shelter, which is split in two – a gas ring for the public walkers, and hot drinks, biscuits, blankets and warm clothes for the Ultimate Hikers.

At the shelter, briefly, there is peace. The clouds sweep north to reveal golden tussock tumbling into the Arthur Valley below, and kea soaring from Mt Balloon to Mt Hart, and Mt Hart to Mt Eliot, their cries piercing and prehistoric in the fleeting reprieve of silence.

Then, another cry, different. A whirr, a bashing, a mechanical stirring of the crisp alpine air. A chopper soars up the valley, swooping down to land outside the shelter. Has someone fallen, been injured – is this a medical evacuation?

A guide from Ultimate Hikes runs out to greet the chopper, carrying a sack in his hand, bent low to avoid the chopper’s blades. Quickly, he throws the bag in the chopper and grabs a similar bag from the pilot; the entire exchange taking less than a minute before the chopper shoots directly upwards and rushes back down the valley.

“What’s in the bag?” I shout to the guide, as he runs to his clients in the shelter, where heaters and steaming mugs of Milo are fogging up the windows.

“Blankets,” he shouts back. “Clean blankets – we’ve just had them washed.”