When famed polar explorer Sir Ernest Shackleton discovered Minnesota at the far edge of the Ross Ice Shelf in the waning decades of the 19th Century, he instantly grasped the challenges this barren tundra would present to human habitation. Granted, Shackleton was not the first one here. Since the 1850s, Scandinavian tribesmen had roamed over the ice pack in search of plentiful mastodons. Shuddering around snow-damp fires, they filled their cheeks with hair-matted rump steaks, and rubbed the half-roasted fat on their pale Viking skin as a primitive form of insulation. (These hunter-gatherers were clever and resourceful, making use of every part of the beast: Modern anthropologists have noted that after the hunters bashed in the mastodon's skull with a chipped rock, or a heavy branch, they'd scoop up the blood-clotted cerebral fluid that had drained into the ice with a carved tusk. This delicacy marked the New World's first attempt to create what the Italians called "gelato"--which would later be known by the more American name of "snow cone.") Yes, life in Minnesota was brutal and brief. Shackleton's earliest diaries took note of the vast number of tribe members who had lost digits and eyelids to the unrelenting arctic winds and deep freezes: "This forbidding continent turns its hapless inhabitants into so many lepers," he wrote, looking at one noseless clan of frostbitten aboriginals. So it was that the polar explorer, on the date of February 2, 1879, set off by penguin train to the tropical latitudes of Dubuque, Iowa. (Bad photography and popular lore would lead period observers to claim that Shackleton had left on a sled hauled by 10,000 groundhogs--a preposterous notion that nonetheless gave birth to the popular Judeo-Christian feast day celebrating the shadow-fearing rodent.) And, in subsequent years, the descendants of those shivering noseless wretches whom Shackelton left behind have followed the trail forged by their man-god, escaping the ice pack that blocks the waters around the state in February by climbing aboard airplanes bound for Cancún. When the tribes return in March, the reindeer and seals can be slaughtered in abundance, marking the onset of the locals' rutting season, which they call spring.