This species has a short, chunky body covered with brownish-grey fur, with a thin dark stripe along the back and a yellow line along its sides.

In winter, it is covered with white fur, and develops enlarged digging claws on its front feet.

They feed on grasses, sedges and other green vegetation in summer, and twigs of willow, aspen, and birches in winter.

Lemming populations go through a three- or four-year cycle of boom and bust.

Remains of these animals dating back to the end of the last ice age have been discovered in the Ottawa valley, far south of their current range.