The approximate sources of the Brahmaputra and Sutlej rivers have been known for 150 years, the main protagonists in their identification being explorers Edmund Smyth, Sven Hedin, and Swami Pranavananda in the 19th and 20th centuries. These rivers, along with the Indus and Karnali, rise near Mt. Kailash, the holy mountain on the Tibetan Plateau, north of Nepal’s far northwest frontier.

Hedin identified the Kubi glaciers as the approximate source of the Brahmaputra, and this remained the status quo until the mid-1930s, when the Indian holy man Pranavananda suggested that the river emanated from the Chemayungdung Glacier farther west. This is nearer to today’s accepted source.

I made journeys to the south side of the Kubi glaciers in 2012, 2016, and 2017 to check out possible mountains that were the farthest from the snout of the Kubi Glacier system, most notably Kubi Kangri (6,721m), climbed by a Japanese team in 2007. That was about the last time any peak permit was given from the Tibet (China) side of western Nepal’s long border.

On seven expeditions between 2007 and 2019, I also looked at the Kanti Himal and Gorakh Himal, which drain into the Kubi Tsangpo system from peaks such as Langtachen, Gorakh, Assajya Tuppa, and Ngomodingding. Furthermore, I looked at unclimbed peaks in the Changla Himal at the top of the Chemayungdung Glacier.

Meanwhile, in 2011, researchers from the Chinese Academy of Sciences (CAS) completed a first-of-its-kind study to pinpoint the sources of the Brahmaputra and Indus rivers. They found the length and drainage of both rivers exceeded earlier estimates. Researchers from the Chinese Academy of Sciences (CAS), a think tank in Beijing, used remote-sensing satellite images and data from several expeditions to the Tibetan Plateau to map the source of the Brahmaputra (known as the Yarlung Tsangpo in Tibet). They placed its source on the Angsi Glacier (a.k.a. Nanser Glacier), which drains northeast from the Ganglung Kangri massif. (The next glacier to the east, the Chemayungdung, was earlier thought to be the source.) The CAS study mapped the river’s total length at 3,848kms; earlier studies had estimated it to be 2,900kms to 3,300kms. They also more accurately estimated the drainage area at 712,035 square kilometers; earlier estimates had ranged from 520,000 square kilometers upwards.

I decided in 2019 to attempt Ganglung Kangri (6,256m) and, more importantly, Ganglung Kangri II (6,182m). The latter is the furthest peak up the Angsi Glacier from its terminus and therefore, in my reckoning, the source point of the Brahmaputra. The mountain’s north ridge, stretching into Tibet, divides the Brahmaputra’s Angsi Glacier from the Sutlej’s Ganglung Glacier. From this one ridge, waters end up on either side of the Indian subcontinent: the Sutlej to Karachi in the Arabian Sea and the Brahmaputra to Calcutta in the Bay of Bengal.

The upper basin of the Angsi has two outlets. One drains north into Tibet (the Angsi), and the other flows southeast into Nepal’s Chuwa Khola (Karnali River), eventually meeting the Ganges in India.  The highest summit, Ganglung Kangri I, therefore feeds the Nepal outfall to the Ganges, while Ganglung Kangri II is the feed for the Brahmaputra.

Access to the Angsi Glacier from Tibet is politically impossible, so I decided to find a way to it from the Nepal side, first in 2019 with Nick Colton and Skip Novak. From Simikot, we traveled eight days following the Chuwa Khola to a 5,000m base camp just below Changla pass on the frontier with Tibet. We found a way up the moraine of an unnamed glacier flowing in from the west and put an advanced base at 5,400m. From here we discovered a hidden glacier col at 5,615m on the Tibet border. Crossing this, we were the first onto the Angsi Glacier, which is surrounded by nine peaks above 6,000m, five of which are unnamed. Without snowshoes, we thought it unfeasible to cross the upper plateau toward the Ganglung peaks.

After a gap during two COVID-19 years, I returned to the west side of the Ganglung massif in 2022, this time with Colton and Ed Douglas. Although we were able to see an approach to Ganglung Kangri from this direction, we were completely thwarted by the worst post-monsoon snowfall for decades. [In the spring of 2023, the first ascent of Chandi Himal peak was made from this expedition’s ABC; see report here.]

In the fall of 2023, Colton and I went back to our 2019 base camp east of the Ganglung massif. This time we were joined by Jim Fotheringham and Jim Lowther. Retracing our 2019 route to the border col, the two Jims pushed across the upper basin of the Angsi in very cold conditions, using snowshoes. On October 16, they made the first ascent of Ganglung Kangri II via a south-facing ramp line (AD).

Only Ganglung Kangri II drains into the Brahmaputra, but both Ganglung Kangri I and II drain west onto the Ganglung Glacier. The outflow from this glacier is known as the Tage Chu until it enters Lake Manasarovar, south of Kailash. This is the infant Sutlej. Thus, in making the first visit to the geographical source of the Brahmaputra, our 2023 expedition also made the first visit to one of the sources of the Sutlej.

— Julian Freeman-Attwood, U.K.