Records cluster heavily around Denali National Park and Preserve, with more scattered reports from the North Slope, the Matanuska-Susitna Valley, and the Copper River delta. Those are exactly the well-drained river bluffs, eskers, and tundra slopes where the ground is loose enough for this squirrel to dig without hitting permafrost right away.
Colonies here spend roughly seven months of the year hibernating, letting their body temperature drop below freezing for weeks at a stretch, among the coldest body temperatures ever recorded in a mammal. That leaves a short, frantic summer to feed, mate, and raise a litter of five to ten young. This species is also a key prey source across its range, hunted from the air by golden eagles and from the ground by red foxes, wolves, and wolverines.
Records build through spring, peak in July, and disappear completely from October through March. That’s not sampling bias. For those months, every arctic ground squirrel in the state is asleep underground.
Full species profile
