Interior Alaska is so large -- it basically includes everything that's not on the coasts or in the Arctic -- you can spend a week of hard driving and not explore it all. Or you can spend all summer floating the rivers and still have years of floating left to do before you see all the riverbanks. It's something like what the great mass of America's Midwest once must have been, perhaps a century and a half ago, when the great flatlands had been explored but not completely civilized and Huckleberry Finn could float downriver into a wilderness of adventures. During an Interior summer, nature combines its immensity with a rare sense of gentleness, patiently awaiting the next thunderstorm.

Winter is another matter. Without the regulating influence of the ocean -- the same reason summers are hot -- winter temperatures can often drop to -30°F or -40°F (-34°C or -40°C), and during exceptional cold snaps, even lower. Now the Earth is wobbling over in the other direction, away from the sun. The long, black nights can make Fairbanks, the region's dominant city, feel more like an outpost on a barren planet, far off in outer space. That's when the northern lights come, spewing swirls of color across the dome of the sky and crackling with electricity. Neighbors wake each other and, rising from bed to put on their warmest parkas and insulated boots, stand in the street, gazing straight up. Visitors lucky enough to come at such times may be watching from a steaming hot-spring tub. During the short days, they can bundle up and watch sled-dog racing or race across the wilderness themselves on snowmobiles.

Fairbanks stands second in Alaska in population, with 94,000 in the greater area, but the Interior otherwise is without any settlements large enough to be called cities. Instead, it's defined by roads, both paved and gravel, which are strands of civilization through sparsely settled, often swampy land. Before the roads, development occurred only on the rivers, which still serve as thoroughfares for the Athabascan villages of the region. In the summer, villagers travel by boat. In the winter, the frozen rivers become highways for snowmobiles and sled-dog teams. White homesteaders and gold miners live in the woods, too. Gold rush history is written on the land in piles of old gravel tailings and abandoned equipment, as well as in prettier tourist attractions and historic sites. Gold mining goes on today in small one-man operations and huge industrial works employing hundreds, but today the economy is based more on military and other government spending, the oil industry, and, of course, tourism. You'll find warm rural hospitality and great vistas on these highways, and, perhaps, a sense of slow-river laziness Huck Finn would have recognized.