Mountain Woodland Caribou (Rangifer tarandus) are the most critically endangered mammal in the U.S., with only a few dozen residing for part of the year in the mountainous Selkirks of Northern Idaho and Northeastern Washington State.
In pioneer times, this, and a related sub-species, ranged widely from Maine to Washington State in the northern part of the U.S. Only about 2000 remain word wide.
A small population exists in Canada, near the US Idaho and Washington borders.
Risks to the current populations include climate change, poaching, disturbance from the noise of industrial activities such as oil drilling, mining, artificial light, parasites, disease, and continuous human encroachment including habitat disturbances like road building, development, etc.
This is a very sensitive species, that does not suffer changes and disturbances well.