Domestic (sadly). I think Alaska Zoo should go all out with an educational theme based on high latitude/high altitude domestics...even bringing in a few additional breeds of that nature. Or highlight the Berengian Ecology, and bring in Wisent, Dholes, Saiga, Pzewalski Horses, Lions (if the Amur Tiger won't suffice), Wild Camels, Onagers, Gaunacos, Snow Sheep, and Wild Yaks!!! Maybe just put a couple of signs.....;-)
As someone who raises Domestic Yaks--and writes about their history--I too would love to see a Wild Yak here in North America. The hurdle is that they cannot survive easily below 10,000 feet altitude--physiologically, they cannot cope. So, unless someone wants to establish a facility on top of Mount Baker or on the slopes of Mount Ranier, Denali, Pikes Peak or similar, you will have to buck it up and travel to Asia to see one.
The attached photo is my bull, Rogue, aka Puppydog and Walking Carpet. He is now five years old, around 1400lbs. and will continue to grow for several more years. He comes from stock in Montana that can reach 1800 lbs--and that is not blubber, either!