https://en.wikipedia.org/wiki/James_L._ClarkJames L. Clark, famous taxidermist. The yak is alive in the picture I assume!
I know a worldly sportsman that hunted Marco Polo sheep many times over many years...He says that back in the day they would ride yaks to access remote areas where horses couldn't handle the severe conditions...No food, no water, the cold nor the 15,000 plus foot altitude.I didn't think you could ride a yak.
James L. Clark is also the author of "The Great Arc of the Wild Sheep", an excellent accounting of the wild sheep species from North American desert bighorns in the south, north through the thin horn sheep species, across to the NE Russian/Asiatic bighorns and sweeping southwest through the ranges of the Argalis and Urials to the Mouflon on the Middle East. It's a book well worth reading and owning.