Jitaditya Narzary wrote an interesting piece on the Brokpas, the semi-nomadic yak herders of the Eastern Himalayas:
In Arunachal Pradesh (in Northeastern India) as well as neighboring Eastern Bhutan, the Brokpas spend summers trekking through high mountains in search of grazing pastures. (A similar community in Western Bhutan, the Bjops, does the same). The yaks provide milk, wool, and meat, but the Brokpas are best known for making yak cheese, which is a major component of local cuisine.
Historical accounts on the Brokpas are rare. In the book Assam Adventure, British botanist and adventurer F Kingdon Ward describes hiking to Tibet through these regions in the early 1900s and passing industrious yak herders. The Brokpa lifestyle has changed very little since then, but modern infrastructure and climate change are beginning to make this trade unsustainable, and their yak cheese increasingly rare.
Unlike pule, chhurpi (yak cheese) is much cheaper:
“One kilogram of chhurpi usually sells for anything between INR 400 to 600 ($5-$8) in the local markets,” [Sange] Norbu says.