BORASU PASS TREK

Borasu Pass (5,450m / 17,880 ft) is one of the most prestigious and challenging cross-over treks in the Indian Himalayas, bridging two legendary mountain kingdoms across the Great Divide. Connecting the green alpine amphitheaters of Har Ki Dun in Uttarakhand's Tons Valley with the stark, granite cliffs of Kinnaur's Baspa Valley in Himachal Pradesh, this expedition retraces an ancient trans-Himalayan trade route.

For centuries, villagers of Osla and Gangad traversed this high glacial pass to trade wool, salt, and local grains with the frontier villages of Chitkul and Sangla. The trek begins from the historic mountain hub of Sankri, following the gushing Supin river through ancient wooden hamlets and along pine-scented trails into the cradle-shaped Har Ki Dun valley—steeped in local mythology as the pathway to heaven beneath the Swargarohini Massif.

As the route ascends beyond the emerald meadows of Maninda Tal and the grazing grounds of Ratta Tho toward Upper Lamjunga, the landscape transforms into rugged high-altitude wilderness dominated by chaotic boulder fields, lateral moraines, and hanging glaciers.

The summit push is a serious mountaineering achievement. Starting long before dawn, trekkers roped up with microspikes and ice axes navigate across the crevassed Zupica/Borasu Glacier before scaling a steep 70° to 75° ice and snow wall leading directly to the summit saddle at 5,450 meters. Standing atop the border ridge reveals breathtaking panoramas of the Swargarohini range, Bandarpunch, Black Peak, and the distant jagged frontier of Tibet and Kinner Kailash.

The descent into Himachal Pradesh involves negotiating a sharp 50-meter technical drop using fixed ropes and controlled rappelling techniques into the Baspa Valley. Traversing lush alpine meadows alongside glacial streams, the expedition culminates at Chitkul—India's last inhabited village on the Indo-Tibetan border—offering a dramatic cultural transition from Garhwali architecture to Kinnauri Buddhist heritage.