Borasu Pass Trek

Borasu pass trek is one such lesser-known high-altitude Himalayan mountain trek lying in the Garhwal Himalayas of India. Borasu Pass Trek is a very unique trek since it divides two different states of India: Uttarakhand and Himachal Pradesh. Moreover, Borasu Pass also falls near the border of Tibet. It is believed that the Borasu Pass, also known as Barasu Pass, was used as a trade route between Har ki Dun Valley and Kinnaur Valley in older days. Can you imagine the beauty of this trek during that time when the local people may have walked on the trails about 500-1000 years ago? What a spectacular beauty this high-altitude Himalayan Pass may have offered to the traders passing through it. Isn't it? Instead of traders, these days, this trek is sought after by the trekkers looking for challenging treks. 

Borasu pass divides Uttarakhand from Himachal Pradesh and it is located near the border of Tibet. The Borasu Pass trek starts from the Tons Valley in Uttarakhand and ends at the Baspa Valley in Himachal Pradesh. This trek falls into the Govind Pashu Vihar National Park. Both Tons and Baspa Valley are named after the names of the respective rivers that flow through these valleys. Tons river flows through Tons Valley in Uttarakhand and merges with the sacred river Yamuna. Whereas the Baspa River flows through the Baspa Valley and merges with the Sutlej river.

By embarking on the Borasu pass trek, you will traverse through remote Himalayan villages like Osla, where you will get a chance to observe the unique ancient mountain architecture, culture and lifestyle of the villagers who live in these remote Himalayan villages. With every passing day, the Borasu Pass Trek will reveal astonishing beauty before you. From the village trails, this trek will take you to the beautiful vast alpine meadows and lush green forests of Pine, Bhojpatra and Rhododendrons; You will hike through ridges and witness the spectacular Marinda Tal which is a glacial lake. From there you will trek to some challenging terrains where you will encounter steep climbs and descends through moraines, glaciers and snow-capped mountains. Starting from a small village of Uttarakhand, this trek will take you to the Chitkul village of Himachal Pradesh.

During the Borasu pass trek, you will be able to see some spectacular high mountain peaks of Uttarakhand Garhwal Himalayas like Swargarohini, Bandarpoonch, Kala Nag (AKA Black Peak), Bonga Peak, Bali Pass and Dhumdhar Kandi Pass. From the Barasu Pass, if you look back, you will see the astonishingly beautiful Har ki dun Valley.

History of Borasu Pass Trek

Borasu Pass lies between Har Ki Dun (Uttarakhand) and Baspa Valley (Himachal Pradesh and connects Tons and Baspa rivers. Some people believe that the name 'Borasu' is derived from the local language- 'Bora' which means enormous or vast; it suggests the wide passage between the valleys.

Local people connect Borasu Pass with the epic Mahabharata and believe that Pandavas took this route on their way to heaven (Swargarohini). In early centuries, Borasu Pass served as a trading and seasonal route among traders, shepherds and pilgrims for moving between Tons and Baspa valleys.

Borasu Pass region was under the influence of small Himalayan kingdoms such as Garhwal Kingdom (Uttarakhand) and Bushahr State (Himachal). However no major battles took place here but the Borasu Pass region was crucial for hidden movement during conflicts and trade deals. Tribes like Bhotias and Rajis used this pass seasonally for grazing and trade. 

In the late 1800s to 1900s, British surveyors and explorers discovered the pass during mapping and marking but still it was not used widely. In recent decades, Borasu Pass gained attention among serious mountaineers and trekkers due to its remoteness and natural alpine beauty. Now it's a part of a thrilling high-altitude trek from Har Ki Dun to Chitkul among the trekkers.

Highlights of Borasu Pass Trek

Dramatic High-Altitude Landscapes:

Borasu Pass trek is known for its dramatic high-altitude landscapes which keep changing as you proceed. Here you will cross surreal alpine terrain, dense forests, bugyals (meadows), glaciers, moraine fields and rocky ridges that make a dream trek for seasoned trekkers. 

Rich Himalayan Flora:

On the lower altitude of Borasu Pass trek (up to 3,500m), you pass through the dense forests of blue pine, deodar and rhododendron. Beautiful Himalayan flora like primulas, anemone and balsam are full-blown during the summer season. Medicinal herbs like brahmi and jatamansi are also found here.

Unique Fauna Sightings:

In Borasu Pass region, you may spot rare and high-altitude wildlife including, Himalayan blue sheep (bharal), Himalayan monal (state bird of Uttarakhand), musk deer, red fox, lammergeier vulture and snow leopard (rare).

Har Ki Dun Campsite:

Har Ki Dhun is a popular trek base used by trekkers for nature sightings and acclimatization. It is located in a hanging valley and surrounded by snow-capped peaks like Hata Peak, Black Peak and Swargarohini. 

Ratha Tho or Marinda Tal:

Ratha Tho or Marinda Tal is a lesser-known meadow near a glacial lake. It is a great spot for watching high-altitude birds and wildflowers. It acts like a stage ground before hitting the high glacier regions.

Cultural Crossroads:

The remote villages like Osla and Chitkul provide cultural insight into local architecture, customs, mythology and festivals. The temples and wooden houses display beautiful Kinnauri and Garhwali traditions.

Difficulty Level of the Borasu Pass Trek

Borasu Pass trek is considered a moderate to difficult and high-altitude trek. It is located at the altitude of approx 5,450 m (17,880 ft) which makes it one of the most difficult cross-border treks in the Indian Himalayas.

Borasu Pass trek is not suitable for kids, families and beginners. It demands physical fitness, mental endurance and prior high-altitude trekking experience. The trek duration is typically 8 to 9 days. Trekkers have to walk 6 to 9 hours daily along with covering the difficult and uneven terrain.

The terrain of Borasu Pass trek is highly diverse. It starts with dense forests and traditional villages in the Govind Pashu Vihar region and opens up to vast alpine meadows, moraine fields, steep climbs, narrow ridges and glacial sections, especially near the pass it becomes more difficult due to snowfields, crevasses and steep ascents.

Trekkers often require technical support as ropes, gaiters, crampons and guidance of experts. Due to it, solo trekking is not advisable. An expert/guide or support team are highly recommended while crossing the pass.

Unpredictable weather sometimes adds more difficulty. The upper regions and the area around the pass mostly have sub-zero temperatures at night. Sudden snowfall, storms and rain are common near the pass.

Borasu Pass trek has remote routes which offer limited emergency exits. The trek ends near Chitkul which falls in an isolated region.

In short, Borasu Pass trek is best suited for experienced trekkers with good health, stamina and willingness. It takes you to a beautiful place but also demands seriousness in trekking and preparation. 

Best Time to Visit Borasu Pass Trek

The best time to do the Borasu Pass trek is from May to June and From September to mid-October. During this time, weather conditions are favourable for trekking and crossing the pass.

May to June

During this time, snow on lower altitudes starts melting but on higher altitudes, it is still present. Overall, it’s more settled and avalanche risk is reduced. Temperature is relatively moderate: around 6°C to 14°C in day time and can be below 0°C at night time; trekkers must stay updated on the weather forecasts. The forests are greener and flowers are bloomed. On lower trails alpine flora looks very mesmerizing. 

September to mid-October

Post monsoon, weather is more reliable as rainfall subsides by early September. Sky is clearer and mountain peaks are visible. Daytime temperature is around 4°C to 12°C and at nighttime, it usually drops below 0°C, depending on lower and higher altitudes. From October, weather conditions can turn cooler so it's advisable to complete the trekking before mid October.

Months to Avoid 

Trekkers should avoid the monsoon season (July-August) due to heavy rainfall. It increases the risk of landslides and makes visibility very poor. Trails become slippery and leech-infested. Similarly, from mid-October to April is also not considered favourable due to cold temperature and heavy snowfall blocks the pass.

How to Reach Borasu Pass Trek

To trek in Borasu Pass, start your journey by reaching Dehradun. You can fly into Jolly Grant Airport or can take an overnight train or bus to reach Dehradun. Dehradun is well-connected from major Indian cities.

From Dehradun, take a shared taxi or cab to go to Sankri village. From Dehradun to Sankri, it takes roughly 7 to 9 hrs.

From Sankri, drive to Taluka (about 1 hr). From Taluka, the trek officially begins. Trek to Seema/Osla along the Supin river and passing through Dhatmir and Gangaad (approx 5-6 hrs).

The next morning, ascend to Har Ki Dun (3,510 m). Har ki Dun is a picturesque cradle-shaped valley. Ascent takes almost 4-5 hrs (10 km). 

The next day, trek to Ratha Tho (4-5 hrs) via Morinda Tal. Take an overnight stay here. Next morning, trek to Borasu Pass Base Camp at Upper Lamjung (3-4 hrs). 

Summit Borasu Pass early in the morning then descend to Bonga (7-8 hrs) in Himachal Pradesh.

The last day, descent through flower meadows into Chitkul (15 km, 7-8 hrs). Chitkul is the last village before the Tibetan border. From Chitkul, arrange transport back to Sankri or onward destinations.