The yak burgers I recently savored came from a farm in Colorado. I was unaware though that yak were being raised locally, in two small farms in Vermont. They might be the only yak farms in the northeast region.
The Vermont Yak Company is located in Waitsfield, Vermont, (in the Mad River Valley) not too far from Burlington. Their site states: "Vermont Yak Company is introducing this spirited Tibetan animal to Vermont as a way to bring new variety to the local food movement, as a contribution to a holistic farming effort in which pasture-fed yak would fertilize fields and gardens, and as a multi-faceted revenue source – meat, agritourism, and breed stock are our three primary sales arenas."
They sell various cuts of yak meat including yak burgers, ribs, sirloins, shin steaks, porterhouses, tenderloins, and t-bones. They even sell some organ meats, such as hearts, tongues, and livers. Plus you can get yak sausages and more. Currently, their meats are available on in their local area, though they do hope to eventually expand their distribution.
You can even visit the farm. For more information, check out their Yak blog which has videos of the yaks and farm. You might also want to sign up for their Yak newsletter.
I do hope to visit their farm in the near future and I will report back once I do.