The Mountain weasel is found from Central Russia in the north, to Korea is the southeast, to Northern India in the west. It is the most common mustelid found in Ladakh, India. As its name suggests, the Mountain Weasel lives at high altitudes (11,480 feet or more), in habitats ranging from rocky tundra to more verdant woodland. They nest in rock crevices, tree trunks, or abandoned burrows, and may live near human populations. Home range is unknown. Six subspecies of Mountain Weasel exist, varying in their choice of habitat and fur color. Mountain weasels are very agile. They can run, climb, and swim. They are generally nocturnal, but may hunt during the day. When threatened, they make a loud chirping sound and emit a pungent scent from their anal glands. The exact sociality of this species is unknown, but believed to be solitary.
Mountain weasels are strict carnivores, mainly feeding on pikas and voles, and playing a vital role in limiting population numbers of these rodents. They are also known to eat muskrats, Ground Squirrels, rabbits, small birds, lizards, frogs, fish, and insects.