The Dudh Kosi river originates from the high-altitude areas of Mount Everest (8848 metres) and the snow and glacier melt contributes significant portion of streamflow, especially during the dry season.

A team of sixteen men, including fourteen Czechs and two Slovaks, had been gathered and on 4 January 1973 they set on the journey from Děhylov by cars (notably using customized Tatra 138 that had to survive over 30,000 km forth and back).

They used 4 metres long fiberglass slalom-style kayaks specially designed by Pyranha Canoes with extra buoyancy and reinforcement.

The expedition is notable for taking place in September to avoid ice and when the water was high to set new altitude record.

[11] But the high water flow had its downside — many parts were too dangerous and had to be omitted; the result was that just two boats out of eleven survived to the end at the confluence with Sun Kosi.

Note that both expeditions didn't embark on Dudh Kosi but rather on Lobuche which is the river formed by the Khumbu Glacier and which runs around Pheriche.