The Thorong La Pass is the highest point on the Annapurna Circuit trek and also one of the highest trekking passes in the world. Survival and success here in the Thorong La Pass depend upon the pillars like proper acclimatization, early timing, and specialized gear.
Scroll down this blog to learn more about the Annapurna Circuit pass crossing survival guide with altitude tips, best seasons, gear, strategy, and how to react in emergency situations.
Thorong La Pass is the highest point on the Annapurna Circuit, standing at an elevation of 5,416 meters. It is situated in the Damodar Himal range of central Nepal and connects the Manang district to the east with the Mustang district (sacred Muktinath temple) to the west.
The Thorong La pass route starts from Manang, goes through Yak Kharka, Thorong Phedi, or High Camp, Thorong La, and ends at Muktinath Temple. This route is also called the Annapurna Circuit pass crossing, as the trekkers use this route during the Annapurna Circuit trekking or Annapurna Circuit with Tilicho Lake trek.
The ascending route is a steep, challenging, but well-trodden and zigzagging trail. The trekkers going through this trek need to be fit and healthy on the cardiovascular level. The descending route is a dramatic and steep drop from the pass to the sacred site of Muktinath Temple.
Manang
Manang is a critical acclimatization stop for the Annapurna Circuit trekkers. They spend two nights here. During their stay, they take day hikes to Ice Lake or Gangapurna Lake.
The Thorong Phedi base camp is a safe place. Here, the trekkers get quality sleep, as it is at a lower altitude.
The high camp is the starting point for the climb. It shortens the climb on the crossing day. But there is a higher risk of altitude sickness during the stay in the high camp.
Muktinath is an end after crossing the Annapurna Circuit pass crossing route. The place is safe, but to reach the Muktinath temple, you have to be ready to push your knees.
Crossing Thorong La Pass is not an easy job. The trekkers need to face the altitude sickness risks while crossing this. Because at the elevation of Thorongla Pass, the oxygen levels are approximately 50% of those at sea level. And to cross this pass, the trekker’s body has to work twice as hard for every breath and step.
The primary altitude risk is for acute mountain sickness (AMS). It is the most common form and affects 50% to 75% of trekkers. The AMS feels like a severe hangover. And then comes the high-altitude pulmonary edema (HAPE). It is a life-threatening buildup of fluid in the lungs.
Some trekkers may also develop the high altitude cerebral edema(HACE). It is as dangerous as HAPE. In HACE, the trekker’s brain swells. After this, the trekkers lose coordination similar to drunken people.
The trekkers should be aware if they experience any of the red line symptoms, like
If the trekkers want to avoid altitude sickness, they should follow the key prevention strategies, like
And in case of emergency, the trekkers should descend immediately without wasting any time at least 500 to 1,000 meters. Remember one thing: never descend alone. If the victims cannot walk, use a horse, porter, or yak to move them down.
If the symptoms appear at night and it is severe (confusion or fluid in lungs), descend immediately using headlamps. And if the professional takes time, buy time with the medications like dexamethasone (for HACE), nifedipine (for HAPE), and acetazolamide (AMS).
The best time to cross the Thorong La Pass is during autumn or spring. But still, the trekkers should have to start between 3:00 AM and 5:00 AM to avoid dangerous high winds after 10:00 AM.
Autumn is the peak trekking season. In this season, the weather of the pass is stable, and the views of the mountains become clear. If I had to choose the best month in autumn, October is the one. In October, there is minimal snow risk and comfortable temperatures.
Spring is the second best season to cross the Thorong La Pass. The season offers the blooming rhododendron and warmer temperatures. But still, the lingering snow can make the pass icy, especially in March. So, it's better to use the microspikes for safe passage.
And after the best seasons, the trekkers sound out about the winter and monsoon season. The winter comes with a high risk of heavy snowfall, extreme cold, and potential pass closures, while the monsoon season is known for heavy rains, slippery trails, leeches at lower elevations, and landslide risks.
For crossing the Thorong La Pass, the trekkers will need technical gear, which is non-negotiable for a safe crossing. The summit push needs these gears.
The gear includes footwear (sturdy, waterproof, and well-broken-in trekking boots with ankle support), trekking poles, a headlamp with extra batteries, UV protection (Category 4 sunglasses or glacier goggles), and crampons or microspikes.
To manage the body temperature while crossing the Thorong La Pass, the trekkers will need a 4-layer clothing system. The layers are base layer, mid layer, insulating layer, and outer shell. All these layers have unique benefits during the pass crossing.
The base layers include the moisture-wicking thermal tops and bottoms. The mid layer includes a fleece jacket and pullover. The insulating layer includes a high-fill down jacket (rated for sub-zero). And the outer shell includes a waterproof and windproof jacket (e.g., Gore-Tex).
The other accessories include mittens, a warm beanie, and a neck buff.
Besides the critical technical gear and 4-layer clothing system, the trekkers will also need the health and safety essentials.
Those essentials include a sleeping bag (professional-grade bag rated to -10°C to -15°C), altitude meds (consult doctor), insulated bottles (with at least 2L of water capacity), high-energy snacks (like nuts or chocolate), UV purifiers, or chlorine/iodine tablets.
Documentation and logistics are also an important part of the Horongla Pass crossing. The trekkers need to obtain the permits. There are no ATMs past Jomsom, so cash may be required. And insurance covering trekking up to 6,000 m and including emergency helicopter evacuation is needed.
The golden rule for the Thorong La Pass crossing is to walk slowly, slowly. The trekkers should never skip the mandatory rest day in Manang. This day can be used to climb high and sleep low to hike to Ice Lake or Gangapurna Lake. This will help the body to adapt.
The sleeping altitude gain should be 300-500 m per day above 3,000 meters. And always trek counterclockwise from Manang to Muktinath.
The trekkers should be ready for the 8-10 hour test of endurance. The pass crossing starts between 3:00 AM and 4:00 AM. and the trekkers must reach the summit before 10:00 AM to avoid the "wind tunnel" effect.
Then, the descent time comes. It is a 1600 m drop to Muktinath. The trekkers should use the trekking poles and keep a controlled and steady pace to avoid injury. Otherwise, it may be punishing on the knees.
The trekkers need to follow the vital safety protocol to survive in the Thorong La Pass crossing. They should drink 4–5 liters of water daily, eat high-carb meals (like garlic soup or dal bhat), and descend immediately in case of emergency. The most important thing not to forget is to hire a licensed and professional guide.
Besides the altitude sickness risks, there are various emergency situations that will come during the Thorong La Pass crossing. The trekkers should be prepared for all.
The pass is a natural wind tunnel. The sudden storms can cause whiteouts. At this time, the visibility drops to zero, and the trails vanish.
During the crossing, the trekkers will be exposed to temperatures below -20°C (-4°F) combined with high winds. This can lead to hypothermia and frostbite.
The heavy snowfalls can increase the risk of avalanches on the steep approach. Also, the descent to Muktinath is long and often covered in black ice and loose scree, leading to falls.
In any case of serious altitude sickness, whether it is HACE or HAPE, the only way is to descend immediately to a lower altitude.
If the case is critical, where the trekkers cannot walk, the helicopter rescue is the primary option. The cost of the helicopter rescue may be high, so having insurance is best.
In the major disasters like avalanches or landslides, the Himalayan Rescue Association (HRA) office in Manang, as a coordination hub, can be used. It is managed by the Nepal Army and civilian agencies.
The Thorong La Pass is Strenuous due to extreme altitude.
The crossing day from Thorong Phedi, or high camp, to Muktinath takes 7 to 10 hours. In this time, 4–6 hours is needed to reach the summit and 3–4 hours is needed for the steep downhill to Muktinath.
The trekkers are advised to start their ascent between 3:30 AM and 4:30 AM. Because after 10:00 AM, the high-velocity winds typically pick up. These high-velocity winds make the pass dangerous with poor visibility.
Yes, the trek is suitable for beginners, but only for the fit beginners with proper preparations. No technical skills are required. But cardiovascular strength and endurance are important.
