We will affirm the endangered status for the southern mountain caribou distinct population segment (DPS) of woodland caribou (Rangifer tarandus caribou). This determination amends the current listing of the southern Selkirk Mountains population of woodland caribou by defining the southern mountain caribou DPS, which includes the southern Selkirk Mountains population. The southern mountain DPS consists of 17 subpopulations (15 extant, 2 extirpated), including the currently listed southern Selkirk Mountains population, a transboundary population that moves between British Columbia, Canada, and northern Idaho and northeastern Washington in the United States. We reaffirm the existing critical habitat for the DPS as previously defined; the amount is approximately 30,010 acres. The effect of this regulation will be to amend the listing of this species in the List of Endangered and Threatened Wildlife.