Crossing the Thorong La pass

It may be the lowest way to cross between the Annapurna and Dhaulagiri Ranges – home to the 10th and 7th highest mountains in the world respectively – yet it is the highest point on the Annapurna Circuit trek. And indeed at 5,416m the highest pass in the world. From the top, the valleys, peaks and rocky slopes of the Annapurna Massif are laid out like a sublime, breathtaking blanket. It is also the point where some treks will end – as snow or altitude sickness necessitates retracing steps back down the Marsyangdi Valley. And while this trek has a reputation for being within the reach of most people of reasonable fitness – crossing the Thorong La pass should never be taken lightly.

What does crossing the Thorong La pass entail?

This is the longest day of the trek, and you can expect an early start, typically leaving the Thorong high camp or Thorong Phedi around sunrise at 6am to give you plenty of time to take things slowly, as well as avoid the worst of the strong winds that can pick up later in the day. Dependent on your fitness, and how you find the altitude before you reach the top of the pass and head back down the steep slope to spend the night in Muktinath, you’re looking at somewhere between 9 and 12 hours of walking – with plenty of breaks thrown in.

You won’t be on your own on your journey up and over the pass – this route is busy with trekkers in the peak season and still used regularly by local traders as the Annapurna roads have yet to penetrate this far.
While most treks will be scheduled to coincide with the best weather conditions for hiking in the Annapurna, mountain weather is notoriously changeable and snow on the Thorong La pass is a possibility, particularly in winter. It is possible to trek in the winter months when the air is particularly clear, there is great visibility and there’s often not another soul in sight on the pass. However the pay-off is the cold – which is biting at altitude – and snow, which can block the pass and necessitate you turning round to retrace your steps down the Marshyangdi Valley.

How difficult you find this day will depend mostly on how you adjust and cope with the altitude – but even if you have acclimatised you should be prepared for a long, often cold, day of hiking – a hard, relentless slog uphill, followed by a steep, knee-crunching descent to Muktinath in changeable weather.

Acclimatisation and altitude sickness

Few people will feel wholly comfortable above 5,000m in altitude – and headaches, minor breathlessness and some nausea are common at this height. However, the Annapurna Circuit offers plenty of acclimatisation before you reach the pass itself – you will have been trekking for around 8 to 15 days and gradually gaining altitude – and as a result most people suffer only mild symptoms. There’s a rule to aid acclimatisation in high-altitude trekking – climb high and sleep low – and given the up-and-down nature of the trail as it winds along the Marsyangdi Valley on the way to Thorong La, you’ll mostly be adhering to this mantra.
Travel Team
If you'd like to chat about Annapurna circuit or need help finding a vacation to suit you we're very happy to help.

The 2014 disaster

On 14 October 2014 the Thorong La pass, the Annapurna Circuit’s tough, crowning jewel, became the scene of Nepal’s worst ever trekking disaster. At least 43 people perished (including Nepalese porters and guides) as violent blizzards caused dramatic snowfall, avalanches and white-out conditions.

The Nepali response to the disaster, and how it could have been prevented have been hotly debated, however a few things are certain. A large number of the trekkers crossing the Thorong La pass on that day were woefully ill-equipped for any kind of emergency in the mountains – with many lacking suitable clothing and footwear. And many must have either not heard – or not heeded – the weather warnings circulated in the week leading up to the disaster. The storm – while unusual for October – was not otherwise without precedence in the Annapurna and had been predicted.

So is it safe?

Yes, but it should never be underestimated and there are inherent, undeniable risks involved in trekking to such a remote, and high-altitude environment. While the Annapurna Circuit is often touted as an introduction to trekking in the Himalayas it is not a walk in the park, and far from easy. Its popularity belies its danger and the altitude, changeable mountain weather and difficult terrain must all be treated with respect.

Traveling with a reputable, experienced trekking company, which employs highly trained guides and has access to advice and guidance from leading experts in the region is one way to mitigate the risks and do everything possible to ensure your safety. Ask questions before you go about what qualifications and experience your guides have – in terms of first aid, dealing with altitude sickness, and inclement mountain weather – and what procedures are in place in case of emergencies. And only book when you are satisfied with the responses. You’ll also be provided with detailed kit lists to ensure you have appropriate clothing and walking boots – and are adequately prepared to spend two to three weeks hiking in the Himalayas.
Andrew Appleyard, from our leading Nepal trekking specialists Exodus Travels highlights the safety benefits of using an experienced, reputable tour operator to organise your trek: “We had groups up there along the Annapurna Circuit when the storm hit in 2014, but not on the Thorong La pass. We’d taken advice from our experts on the ground in Nepal –one of whom is the first British woman to climb Manaslu, has reached the Hilary Step on Everest, and has huge amounts of experience and a deep, personal understanding of the risks involved in high-altitude trekking in the Himalayas. Saying that, there is always a risk involved – the weather forecasts can change by the hour – even with the best advice behind you being properly prepared for an emergency is vital.”

Our top safety tips

Use a reputable, experienced tour operator which employs highly-trained guides, and has planned your route to build in plenty of time for acclimatisation to the altitude. Question your tour operator as to what safety procedures they have in place in the case of medical, or environmental emergencies. Prepare for your trek before you travel – see the ‘Am I fit enough?’ page of this guide for training tips. Invest in good quality hiking equipment – walking boots, waterproofs and warm layers – and test these out before your depart for Nepal. Know the symptoms of altitude sickness – the NHS Fit for Travel site has useful information - and tell your guide if you start to feel unwell. Drink plenty of water as you ascend and avoid alcohol.
Written by Sarah Faith
Photo credits: [Page banner: Solundir] [Intro: AjayKumarShrestha] [What does crossing the Thorong La pass entail?: Sergey Ashmarin] [So is it safe?: Schutz]