Ground squirrels and marmots are true hibernators: Unlike other mammals such as brown, grizzly, and polar bears, they sleep for six months straight in a deep coma. This separation between life and death is one of the thinnest lines in the animal world.

A ground squirrel’s heart slows to about six beats a minute, and its body temperature lowers to just above freezing, around 38°F. (In fact, a zoologist at the University of Alaska Fairbanks has found that the core temperature of the Arctic ground squirrel, the northernmost hibernator, can drop to as low as 26°F—six degrees below freezing! Of course, the squirrels don’t freeze; they “supercool.”)

The hibernating squirrel takes a breath every couple of minutes. It uses up half its body weight, since it isn’t eating. If you stuck a needle in a hibernating ground squirrel’s paw, it would take the animal about 10 minutes to begin to feel it.

Ground squirrels provide a large part of the grizzly and wolf diet, and that of scavenger birds’ as well, since they’re a common type of roadkill.

Marmots, similar to woodchucks, are sometimes mistaken for wolverines. They live in large rock outcroppings for protection and have a piercing whistle, which warns of approaching predators or other possible danger. Look for marmots around Polychrome Pass at Denali Park; ask the driver where exactly to see them.

Alaska has a number of other members of the rodent family: shrews, mice, voles, lemmings, and porcupines. Long-tailed and least weasels occupy a wide habitat in the taiga and tundra. Martens are another member of the weasel family, similar to, though much more aggressive than, mink; the pine marten is one of Alaska’s most valuable fur-bearers.

Wolverines are in attendance, though you’d be very lucky to see one. Red foxes are common in the Interior and Southcentral Alaska, and you’re likely to see one at Denali Park; the white Arctic fox is a gorgeous animal, though you’ll only see one in pictures.